Update compiler-rt to 3.7.0 release. This also includes the sanitizer

[FreeBSD/FreeBSD.git] / sys / dev / xl / if_xl.c

/*-
 * Copyright (c) 1997, 1998, 1999
 *      Bill Paul <wpaul@ctr.columbia.edu>.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*
 * 3Com 3c90x Etherlink XL PCI NIC driver
 *
 * Supports the 3Com "boomerang", "cyclone" and "hurricane" PCI
 * bus-master chips (3c90x cards and embedded controllers) including
 * the following:
 *
 * 3Com 3c900-TPO       10Mbps/RJ-45
 * 3Com 3c900-COMBO     10Mbps/RJ-45,AUI,BNC
 * 3Com 3c905-TX        10/100Mbps/RJ-45
 * 3Com 3c905-T4        10/100Mbps/RJ-45
 * 3Com 3c900B-TPO      10Mbps/RJ-45
 * 3Com 3c900B-COMBO    10Mbps/RJ-45,AUI,BNC
 * 3Com 3c900B-TPC      10Mbps/RJ-45,BNC
 * 3Com 3c900B-FL       10Mbps/Fiber-optic
 * 3Com 3c905B-COMBO    10/100Mbps/RJ-45,AUI,BNC
 * 3Com 3c905B-TX       10/100Mbps/RJ-45
 * 3Com 3c905B-FL/FX    10/100Mbps/Fiber-optic
 * 3Com 3c905C-TX       10/100Mbps/RJ-45 (Tornado ASIC)
 * 3Com 3c980-TX        10/100Mbps server adapter (Hurricane ASIC)
 * 3Com 3c980C-TX       10/100Mbps server adapter (Tornado ASIC)
 * 3Com 3cSOHO100-TX    10/100Mbps/RJ-45 (Hurricane ASIC)
 * 3Com 3c450-TX        10/100Mbps/RJ-45 (Tornado ASIC)
 * 3Com 3c555           10/100Mbps/RJ-45 (MiniPCI, Laptop Hurricane)
 * 3Com 3c556           10/100Mbps/RJ-45 (MiniPCI, Hurricane ASIC)
 * 3Com 3c556B          10/100Mbps/RJ-45 (MiniPCI, Hurricane ASIC)
 * 3Com 3c575TX         10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
 * 3Com 3c575B          10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
 * 3Com 3c575C          10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
 * 3Com 3cxfem656       10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
 * 3Com 3cxfem656b      10/100Mbps/RJ-45 (Cardbus, Hurricane ASIC)
 * 3Com 3cxfem656c      10/100Mbps/RJ-45 (Cardbus, Tornado ASIC)
 * Dell Optiplex GX1 on-board 3c918 10/100Mbps/RJ-45
 * Dell on-board 3c920 10/100Mbps/RJ-45
 * Dell Precision on-board 3c905B 10/100Mbps/RJ-45
 * Dell Latitude laptop docking station embedded 3c905-TX
 *
 * Written by Bill Paul <wpaul@ctr.columbia.edu>
 * Electrical Engineering Department
 * Columbia University, New York City
 */
/*
 * The 3c90x series chips use a bus-master DMA interface for transfering
 * packets to and from the controller chip. Some of the "vortex" cards
 * (3c59x) also supported a bus master mode, however for those chips
 * you could only DMA packets to/from a contiguous memory buffer. For
 * transmission this would mean copying the contents of the queued mbuf
 * chain into an mbuf cluster and then DMAing the cluster. This extra
 * copy would sort of defeat the purpose of the bus master support for
 * any packet that doesn't fit into a single mbuf.
 *
 * By contrast, the 3c90x cards support a fragment-based bus master
 * mode where mbuf chains can be encapsulated using TX descriptors.
 * This is similar to other PCI chips such as the Texas Instruments
 * ThunderLAN and the Intel 82557/82558.
 *
 * The "vortex" driver (if_vx.c) happens to work for the "boomerang"
 * bus master chips because they maintain the old PIO interface for
 * backwards compatibility, but starting with the 3c905B and the
 * "cyclone" chips, the compatibility interface has been dropped.
 * Since using bus master DMA is a big win, we use this driver to
 * support the PCI "boomerang" chips even though they work with the
 * "vortex" driver in order to obtain better performance.
 */

#ifdef HAVE_KERNEL_OPTION_HEADERS
#include "opt_device_polling.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/endian.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/socket.h>
#include <sys/taskqueue.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/if_types.h>

#include <net/bpf.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/rman.h>

#include <dev/mii/mii.h>
#include <dev/mii/mii_bitbang.h>
#include <dev/mii/miivar.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>

MODULE_DEPEND(xl, pci, 1, 1, 1);
MODULE_DEPEND(xl, ether, 1, 1, 1);
MODULE_DEPEND(xl, miibus, 1, 1, 1);

/* "device miibus" required.  See GENERIC if you get errors here. */
#include "miibus_if.h"

#include <dev/xl/if_xlreg.h>

/*
 * TX Checksumming is disabled by default for two reasons:
 * - TX Checksumming will occasionally produce corrupt packets
 * - TX Checksumming seems to reduce performance
 *
 * Only 905B/C cards were reported to have this problem, it is possible
 * that later chips _may_ be immune.
 */
#define XL905B_TXCSUM_BROKEN    1

#ifdef XL905B_TXCSUM_BROKEN
#define XL905B_CSUM_FEATURES    0
#else
#define XL905B_CSUM_FEATURES    (CSUM_IP | CSUM_TCP | CSUM_UDP)
#endif

/*
 * Various supported device vendors/types and their names.
 */
static const struct xl_type xl_devs[] = {
        { TC_VENDORID, TC_DEVICEID_BOOMERANG_10BT,
                "3Com 3c900-TPO Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_BOOMERANG_10BT_COMBO,
                "3Com 3c900-COMBO Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_BOOMERANG_10_100BT,
                "3Com 3c905-TX Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_BOOMERANG_100BT4,
                "3Com 3c905-T4 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_KRAKATOA_10BT,
                "3Com 3c900B-TPO Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_KRAKATOA_10BT_COMBO,
                "3Com 3c900B-COMBO Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_KRAKATOA_10BT_TPC,
                "3Com 3c900B-TPC Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_CYCLONE_10FL,
                "3Com 3c900B-FL Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_10_100BT,
                "3Com 3c905B-TX Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_CYCLONE_10_100BT4,
                "3Com 3c905B-T4 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_CYCLONE_10_100FX,
                "3Com 3c905B-FX/SC Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_CYCLONE_10_100_COMBO,
                "3Com 3c905B-COMBO Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_TORNADO_10_100BT,
                "3Com 3c905C-TX Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_TORNADO_10_100BT_920B,
                "3Com 3c920B-EMB Integrated Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_TORNADO_10_100BT_920B_WNM,
                "3Com 3c920B-EMB-WNM Integrated Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_10_100BT_SERV,
                "3Com 3c980 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_TORNADO_10_100BT_SERV,
                "3Com 3c980C Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_SOHO100TX,
                "3Com 3cSOHO100-TX OfficeConnect" },
        { TC_VENDORID, TC_DEVICEID_TORNADO_HOMECONNECT,
                "3Com 3c450-TX HomeConnect" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_555,
                "3Com 3c555 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_556,
                "3Com 3c556 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_556B,
                "3Com 3c556B Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_575A,
                "3Com 3c575TX Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_575B,
                "3Com 3c575B Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_575C,
                "3Com 3c575C Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_656,
                "3Com 3c656 Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_HURRICANE_656B,
                "3Com 3c656B Fast Etherlink XL" },
        { TC_VENDORID, TC_DEVICEID_TORNADO_656C,
                "3Com 3c656C Fast Etherlink XL" },
        { 0, 0, NULL }
};

static int xl_probe(device_t);
static int xl_attach(device_t);
static int xl_detach(device_t);

static int xl_newbuf(struct xl_softc *, struct xl_chain_onefrag *);
static void xl_tick(void *);
static void xl_stats_update(struct xl_softc *);
static int xl_encap(struct xl_softc *, struct xl_chain *, struct mbuf **);
static int xl_rxeof(struct xl_softc *);
static void xl_rxeof_task(void *, int);
static int xl_rx_resync(struct xl_softc *);
static void xl_txeof(struct xl_softc *);
static void xl_txeof_90xB(struct xl_softc *);
static void xl_txeoc(struct xl_softc *);
static void xl_intr(void *);
static void xl_start(struct ifnet *);
static void xl_start_locked(struct ifnet *);
static void xl_start_90xB_locked(struct ifnet *);
static int xl_ioctl(struct ifnet *, u_long, caddr_t);
static void xl_init(void *);
static void xl_init_locked(struct xl_softc *);
static void xl_stop(struct xl_softc *);
static int xl_watchdog(struct xl_softc *);
static int xl_shutdown(device_t);
static int xl_suspend(device_t);
static int xl_resume(device_t);
static void xl_setwol(struct xl_softc *);

#ifdef DEVICE_POLLING
static int xl_poll(struct ifnet *ifp, enum poll_cmd cmd, int count);
static int xl_poll_locked(struct ifnet *ifp, enum poll_cmd cmd, int count);
#endif

static int xl_ifmedia_upd(struct ifnet *);
static void xl_ifmedia_sts(struct ifnet *, struct ifmediareq *);

static int xl_eeprom_wait(struct xl_softc *);
static int xl_read_eeprom(struct xl_softc *, caddr_t, int, int, int);

static void xl_rxfilter(struct xl_softc *);
static void xl_rxfilter_90x(struct xl_softc *);
static void xl_rxfilter_90xB(struct xl_softc *);
static void xl_setcfg(struct xl_softc *);
static void xl_setmode(struct xl_softc *, int);
static void xl_reset(struct xl_softc *);
static int xl_list_rx_init(struct xl_softc *);
static int xl_list_tx_init(struct xl_softc *);
static int xl_list_tx_init_90xB(struct xl_softc *);
static void xl_wait(struct xl_softc *);
static void xl_mediacheck(struct xl_softc *);
static void xl_choose_media(struct xl_softc *sc, int *media);
static void xl_choose_xcvr(struct xl_softc *, int);
static void xl_dma_map_addr(void *, bus_dma_segment_t *, int, int);
#ifdef notdef
static void xl_testpacket(struct xl_softc *);
#endif

static int xl_miibus_readreg(device_t, int, int);
static int xl_miibus_writereg(device_t, int, int, int);
static void xl_miibus_statchg(device_t);
static void xl_miibus_mediainit(device_t);

/*
 * MII bit-bang glue
 */
static uint32_t xl_mii_bitbang_read(device_t);
static void xl_mii_bitbang_write(device_t, uint32_t);

static const struct mii_bitbang_ops xl_mii_bitbang_ops = {
        xl_mii_bitbang_read,
        xl_mii_bitbang_write,
        {
                XL_MII_DATA,            /* MII_BIT_MDO */
                XL_MII_DATA,            /* MII_BIT_MDI */
                XL_MII_CLK,             /* MII_BIT_MDC */
                XL_MII_DIR,             /* MII_BIT_DIR_HOST_PHY */
                0,                      /* MII_BIT_DIR_PHY_HOST */
        }
};

static device_method_t xl_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         xl_probe),
        DEVMETHOD(device_attach,        xl_attach),
        DEVMETHOD(device_detach,        xl_detach),
        DEVMETHOD(device_shutdown,      xl_shutdown),
        DEVMETHOD(device_suspend,       xl_suspend),
        DEVMETHOD(device_resume,        xl_resume),

        /* MII interface */
        DEVMETHOD(miibus_readreg,       xl_miibus_readreg),
        DEVMETHOD(miibus_writereg,      xl_miibus_writereg),
        DEVMETHOD(miibus_statchg,       xl_miibus_statchg),
        DEVMETHOD(miibus_mediainit,     xl_miibus_mediainit),

        DEVMETHOD_END
};

static driver_t xl_driver = {
        "xl",
        xl_methods,
        sizeof(struct xl_softc)
};

static devclass_t xl_devclass;

DRIVER_MODULE_ORDERED(xl, pci, xl_driver, xl_devclass, NULL, NULL,
    SI_ORDER_ANY);
DRIVER_MODULE(miibus, xl, miibus_driver, miibus_devclass, NULL, NULL);

static void
xl_dma_map_addr(void *arg, bus_dma_segment_t *segs, int nseg, int error)
{
        u_int32_t *paddr;

        paddr = arg;
        *paddr = segs->ds_addr;
}

/*
 * Murphy's law says that it's possible the chip can wedge and
 * the 'command in progress' bit may never clear. Hence, we wait
 * only a finite amount of time to avoid getting caught in an
 * infinite loop. Normally this delay routine would be a macro,
 * but it isn't called during normal operation so we can afford
 * to make it a function.  Suppress warning when card gone.
 */
static void
xl_wait(struct xl_softc *sc)
{
        register int            i;

        for (i = 0; i < XL_TIMEOUT; i++) {
                if ((CSR_READ_2(sc, XL_STATUS) & XL_STAT_CMDBUSY) == 0)
                        break;
        }

        if (i == XL_TIMEOUT && bus_child_present(sc->xl_dev))
                device_printf(sc->xl_dev, "command never completed!\n");
}

/*
 * MII access routines are provided for adapters with external
 * PHYs (3c905-TX, 3c905-T4, 3c905B-T4) and those with built-in
 * autoneg logic that's faked up to look like a PHY (3c905B-TX).
 * Note: if you don't perform the MDIO operations just right,
 * it's possible to end up with code that works correctly with
 * some chips/CPUs/processor speeds/bus speeds/etc but not
 * with others.
 */

/*
 * Read the MII serial port for the MII bit-bang module.
 */
static uint32_t
xl_mii_bitbang_read(device_t dev)
{
        struct xl_softc         *sc;
        uint32_t                val;

        sc = device_get_softc(dev);

        /* We're already in window 4. */
        val = CSR_READ_2(sc, XL_W4_PHY_MGMT);
        CSR_BARRIER(sc, XL_W4_PHY_MGMT, 2,
            BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);

        return (val);
}

/*
 * Write the MII serial port for the MII bit-bang module.
 */
static void
xl_mii_bitbang_write(device_t dev, uint32_t val)
{
        struct xl_softc         *sc;

        sc = device_get_softc(dev);

        /* We're already in window 4. */
        CSR_WRITE_2(sc, XL_W4_PHY_MGMT, val);
        CSR_BARRIER(sc, XL_W4_PHY_MGMT, 2,
            BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
}

static int
xl_miibus_readreg(device_t dev, int phy, int reg)
{
        struct xl_softc         *sc;

        sc = device_get_softc(dev);

        /* Select the window 4. */
        XL_SEL_WIN(4);

        return (mii_bitbang_readreg(dev, &xl_mii_bitbang_ops, phy, reg));
}

static int
xl_miibus_writereg(device_t dev, int phy, int reg, int data)
{
        struct xl_softc         *sc;

        sc = device_get_softc(dev);

        /* Select the window 4. */
        XL_SEL_WIN(4);

        mii_bitbang_writereg(dev, &xl_mii_bitbang_ops, phy, reg, data);

        return (0);
}

static void
xl_miibus_statchg(device_t dev)
{
        struct xl_softc         *sc;
        struct mii_data         *mii;
        uint8_t                 macctl;

        sc = device_get_softc(dev);
        mii = device_get_softc(sc->xl_miibus);

        xl_setcfg(sc);

        /* Set ASIC's duplex mode to match the PHY. */
        XL_SEL_WIN(3);
        macctl = CSR_READ_1(sc, XL_W3_MAC_CTRL);
        if ((IFM_OPTIONS(mii->mii_media_active) & IFM_FDX) != 0) {
                macctl |= XL_MACCTRL_DUPLEX;
                if (sc->xl_type == XL_TYPE_905B) {
                        if ((IFM_OPTIONS(mii->mii_media_active) &
                            IFM_ETH_RXPAUSE) != 0)
                                macctl |= XL_MACCTRL_FLOW_CONTROL_ENB;
                        else
                                macctl &= ~XL_MACCTRL_FLOW_CONTROL_ENB;
                }
        } else {
                macctl &= ~XL_MACCTRL_DUPLEX;
                if (sc->xl_type == XL_TYPE_905B)
                        macctl &= ~XL_MACCTRL_FLOW_CONTROL_ENB;
        }
        CSR_WRITE_1(sc, XL_W3_MAC_CTRL, macctl);
}

/*
 * Special support for the 3c905B-COMBO. This card has 10/100 support
 * plus BNC and AUI ports. This means we will have both an miibus attached
 * plus some non-MII media settings. In order to allow this, we have to
 * add the extra media to the miibus's ifmedia struct, but we can't do
 * that during xl_attach() because the miibus hasn't been attached yet.
 * So instead, we wait until the miibus probe/attach is done, at which
 * point we will get a callback telling is that it's safe to add our
 * extra media.
 */
static void
xl_miibus_mediainit(device_t dev)
{
        struct xl_softc         *sc;
        struct mii_data         *mii;
        struct ifmedia          *ifm;

        sc = device_get_softc(dev);
        mii = device_get_softc(sc->xl_miibus);
        ifm = &mii->mii_media;

        if (sc->xl_media & (XL_MEDIAOPT_AUI | XL_MEDIAOPT_10FL)) {
                /*
                 * Check for a 10baseFL board in disguise.
                 */
                if (sc->xl_type == XL_TYPE_905B &&
                    sc->xl_media == XL_MEDIAOPT_10FL) {
                        if (bootverbose)
                                device_printf(sc->xl_dev, "found 10baseFL\n");
                        ifmedia_add(ifm, IFM_ETHER | IFM_10_FL, 0, NULL);
                        ifmedia_add(ifm, IFM_ETHER | IFM_10_FL|IFM_HDX, 0,
                            NULL);
                        if (sc->xl_caps & XL_CAPS_FULL_DUPLEX)
                                ifmedia_add(ifm,
                                    IFM_ETHER | IFM_10_FL | IFM_FDX, 0, NULL);
                } else {
                        if (bootverbose)
                                device_printf(sc->xl_dev, "found AUI\n");
                        ifmedia_add(ifm, IFM_ETHER | IFM_10_5, 0, NULL);
                }
        }

        if (sc->xl_media & XL_MEDIAOPT_BNC) {
                if (bootverbose)
                        device_printf(sc->xl_dev, "found BNC\n");
                ifmedia_add(ifm, IFM_ETHER | IFM_10_2, 0, NULL);
        }
}

/*
 * The EEPROM is slow: give it time to come ready after issuing
 * it a command.
 */
static int
xl_eeprom_wait(struct xl_softc *sc)
{
        int                     i;

        for (i = 0; i < 100; i++) {
                if (CSR_READ_2(sc, XL_W0_EE_CMD) & XL_EE_BUSY)
                        DELAY(162);
                else
                        break;
        }

        if (i == 100) {
                device_printf(sc->xl_dev, "eeprom failed to come ready\n");
                return (1);
        }

        return (0);
}

/*
 * Read a sequence of words from the EEPROM. Note that ethernet address
 * data is stored in the EEPROM in network byte order.
 */
static int
xl_read_eeprom(struct xl_softc *sc, caddr_t dest, int off, int cnt, int swap)
{
        int                     err = 0, i;
        u_int16_t               word = 0, *ptr;

#define EEPROM_5BIT_OFFSET(A) ((((A) << 2) & 0x7F00) | ((A) & 0x003F))
#define EEPROM_8BIT_OFFSET(A) ((A) & 0x003F)
        /*
         * XXX: WARNING! DANGER!
         * It's easy to accidentally overwrite the rom content!
         * Note: the 3c575 uses 8bit EEPROM offsets.
         */
        XL_SEL_WIN(0);

        if (xl_eeprom_wait(sc))
                return (1);

        if (sc->xl_flags & XL_FLAG_EEPROM_OFFSET_30)
                off += 0x30;

        for (i = 0; i < cnt; i++) {
                if (sc->xl_flags & XL_FLAG_8BITROM)
                        CSR_WRITE_2(sc, XL_W0_EE_CMD,
                            XL_EE_8BIT_READ | EEPROM_8BIT_OFFSET(off + i));
                else
                        CSR_WRITE_2(sc, XL_W0_EE_CMD,
                            XL_EE_READ | EEPROM_5BIT_OFFSET(off + i));
                err = xl_eeprom_wait(sc);
                if (err)
                        break;
                word = CSR_READ_2(sc, XL_W0_EE_DATA);
                ptr = (u_int16_t *)(dest + (i * 2));
                if (swap)
                        *ptr = ntohs(word);
                else
                        *ptr = word;
        }

        return (err ? 1 : 0);
}

static void
xl_rxfilter(struct xl_softc *sc)
{

        if (sc->xl_type == XL_TYPE_905B)
                xl_rxfilter_90xB(sc);
        else
                xl_rxfilter_90x(sc);
}

/*
 * NICs older than the 3c905B have only one multicast option, which
 * is to enable reception of all multicast frames.
 */
static void
xl_rxfilter_90x(struct xl_softc *sc)
{
        struct ifnet            *ifp;
        struct ifmultiaddr      *ifma;
        u_int8_t                rxfilt;

        XL_LOCK_ASSERT(sc);

        ifp = sc->xl_ifp;

        XL_SEL_WIN(5);
        rxfilt = CSR_READ_1(sc, XL_W5_RX_FILTER);
        rxfilt &= ~(XL_RXFILTER_ALLFRAMES | XL_RXFILTER_ALLMULTI |
            XL_RXFILTER_BROADCAST | XL_RXFILTER_INDIVIDUAL);

        /* Set the individual bit to receive frames for this host only. */
        rxfilt |= XL_RXFILTER_INDIVIDUAL;
        /* Set capture broadcast bit to capture broadcast frames. */
        if (ifp->if_flags & IFF_BROADCAST)
                rxfilt |= XL_RXFILTER_BROADCAST;

        /* If we want promiscuous mode, set the allframes bit. */
        if (ifp->if_flags & (IFF_PROMISC | IFF_ALLMULTI)) {
                if (ifp->if_flags & IFF_PROMISC)
                        rxfilt |= XL_RXFILTER_ALLFRAMES;
                if (ifp->if_flags & IFF_ALLMULTI)
                        rxfilt |= XL_RXFILTER_ALLMULTI;
        } else {
                if_maddr_rlock(ifp);
                TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                        if (ifma->ifma_addr->sa_family != AF_LINK)
                                continue;
                        rxfilt |= XL_RXFILTER_ALLMULTI;
                        break;
                }
                if_maddr_runlock(ifp);
        }

        CSR_WRITE_2(sc, XL_COMMAND, rxfilt | XL_CMD_RX_SET_FILT);
        XL_SEL_WIN(7);
}

/*
 * 3c905B adapters have a hash filter that we can program.
 */
static void
xl_rxfilter_90xB(struct xl_softc *sc)
{
        struct ifnet            *ifp;
        struct ifmultiaddr      *ifma;
        int                     i, mcnt;
        u_int16_t               h;
        u_int8_t                rxfilt;

        XL_LOCK_ASSERT(sc);

        ifp = sc->xl_ifp;

        XL_SEL_WIN(5);
        rxfilt = CSR_READ_1(sc, XL_W5_RX_FILTER);
        rxfilt &= ~(XL_RXFILTER_ALLFRAMES | XL_RXFILTER_ALLMULTI |
            XL_RXFILTER_BROADCAST | XL_RXFILTER_INDIVIDUAL |
            XL_RXFILTER_MULTIHASH);

        /* Set the individual bit to receive frames for this host only. */
        rxfilt |= XL_RXFILTER_INDIVIDUAL;
        /* Set capture broadcast bit to capture broadcast frames. */
        if (ifp->if_flags & IFF_BROADCAST)
                rxfilt |= XL_RXFILTER_BROADCAST;

        /* If we want promiscuous mode, set the allframes bit. */
        if (ifp->if_flags & (IFF_PROMISC | IFF_ALLMULTI)) {
                if (ifp->if_flags & IFF_PROMISC)
                        rxfilt |= XL_RXFILTER_ALLFRAMES;
                if (ifp->if_flags & IFF_ALLMULTI)
                        rxfilt |= XL_RXFILTER_ALLMULTI;
        } else {
                /* First, zot all the existing hash bits. */
                for (i = 0; i < XL_HASHFILT_SIZE; i++)
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_HASH | i);

                /* Now program new ones. */
                mcnt = 0;
                if_maddr_rlock(ifp);
                TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                        if (ifma->ifma_addr->sa_family != AF_LINK)
                                continue;
                        /*
                         * Note: the 3c905B currently only supports a 64-bit
                         * hash table, which means we really only need 6 bits,
                         * but the manual indicates that future chip revisions
                         * will have a 256-bit hash table, hence the routine
                         * is set up to calculate 8 bits of position info in
                         * case we need it some day.
                         * Note II, The Sequel: _CURRENT_ versions of the
                         * 3c905B have a 256 bit hash table. This means we have
                         * to use all 8 bits regardless.  On older cards, the
                         * upper 2 bits will be ignored. Grrrr....
                         */
                        h = ether_crc32_be(LLADDR((struct sockaddr_dl *)
                            ifma->ifma_addr), ETHER_ADDR_LEN) & 0xFF;
                        CSR_WRITE_2(sc, XL_COMMAND,
                            h | XL_CMD_RX_SET_HASH | XL_HASH_SET);
                        mcnt++;
                }
                if_maddr_runlock(ifp);
                if (mcnt > 0)
                        rxfilt |= XL_RXFILTER_MULTIHASH;
        }

        CSR_WRITE_2(sc, XL_COMMAND, rxfilt | XL_CMD_RX_SET_FILT);
        XL_SEL_WIN(7);
}

static void
xl_setcfg(struct xl_softc *sc)
{
        u_int32_t               icfg;

        /*XL_LOCK_ASSERT(sc);*/

        XL_SEL_WIN(3);
        icfg = CSR_READ_4(sc, XL_W3_INTERNAL_CFG);
        icfg &= ~XL_ICFG_CONNECTOR_MASK;
        if (sc->xl_media & XL_MEDIAOPT_MII ||
                sc->xl_media & XL_MEDIAOPT_BT4)
                icfg |= (XL_XCVR_MII << XL_ICFG_CONNECTOR_BITS);
        if (sc->xl_media & XL_MEDIAOPT_BTX)
                icfg |= (XL_XCVR_AUTO << XL_ICFG_CONNECTOR_BITS);

        CSR_WRITE_4(sc, XL_W3_INTERNAL_CFG, icfg);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);
}

static void
xl_setmode(struct xl_softc *sc, int media)
{
        u_int32_t               icfg;
        u_int16_t               mediastat;
        char                    *pmsg = "", *dmsg = "";

        XL_LOCK_ASSERT(sc);

        XL_SEL_WIN(4);
        mediastat = CSR_READ_2(sc, XL_W4_MEDIA_STATUS);
        XL_SEL_WIN(3);
        icfg = CSR_READ_4(sc, XL_W3_INTERNAL_CFG);

        if (sc->xl_media & XL_MEDIAOPT_BT) {
                if (IFM_SUBTYPE(media) == IFM_10_T) {
                        pmsg = "10baseT transceiver";
                        sc->xl_xcvr = XL_XCVR_10BT;
                        icfg &= ~XL_ICFG_CONNECTOR_MASK;
                        icfg |= (XL_XCVR_10BT << XL_ICFG_CONNECTOR_BITS);
                        mediastat |= XL_MEDIASTAT_LINKBEAT |
                            XL_MEDIASTAT_JABGUARD;
                        mediastat &= ~XL_MEDIASTAT_SQEENB;
                }
        }

        if (sc->xl_media & XL_MEDIAOPT_BFX) {
                if (IFM_SUBTYPE(media) == IFM_100_FX) {
                        pmsg = "100baseFX port";
                        sc->xl_xcvr = XL_XCVR_100BFX;
                        icfg &= ~XL_ICFG_CONNECTOR_MASK;
                        icfg |= (XL_XCVR_100BFX << XL_ICFG_CONNECTOR_BITS);
                        mediastat |= XL_MEDIASTAT_LINKBEAT;
                        mediastat &= ~XL_MEDIASTAT_SQEENB;
                }
        }

        if (sc->xl_media & (XL_MEDIAOPT_AUI|XL_MEDIAOPT_10FL)) {
                if (IFM_SUBTYPE(media) == IFM_10_5) {
                        pmsg = "AUI port";
                        sc->xl_xcvr = XL_XCVR_AUI;
                        icfg &= ~XL_ICFG_CONNECTOR_MASK;
                        icfg |= (XL_XCVR_AUI << XL_ICFG_CONNECTOR_BITS);
                        mediastat &= ~(XL_MEDIASTAT_LINKBEAT |
                            XL_MEDIASTAT_JABGUARD);
                        mediastat |= ~XL_MEDIASTAT_SQEENB;
                }
                if (IFM_SUBTYPE(media) == IFM_10_FL) {
                        pmsg = "10baseFL transceiver";
                        sc->xl_xcvr = XL_XCVR_AUI;
                        icfg &= ~XL_ICFG_CONNECTOR_MASK;
                        icfg |= (XL_XCVR_AUI << XL_ICFG_CONNECTOR_BITS);
                        mediastat &= ~(XL_MEDIASTAT_LINKBEAT |
                            XL_MEDIASTAT_JABGUARD);
                        mediastat |= ~XL_MEDIASTAT_SQEENB;
                }
        }

        if (sc->xl_media & XL_MEDIAOPT_BNC) {
                if (IFM_SUBTYPE(media) == IFM_10_2) {
                        pmsg = "AUI port";
                        sc->xl_xcvr = XL_XCVR_COAX;
                        icfg &= ~XL_ICFG_CONNECTOR_MASK;
                        icfg |= (XL_XCVR_COAX << XL_ICFG_CONNECTOR_BITS);
                        mediastat &= ~(XL_MEDIASTAT_LINKBEAT |
                            XL_MEDIASTAT_JABGUARD | XL_MEDIASTAT_SQEENB);
                }
        }

        if ((media & IFM_GMASK) == IFM_FDX ||
                        IFM_SUBTYPE(media) == IFM_100_FX) {
                dmsg = "full";
                XL_SEL_WIN(3);
                CSR_WRITE_1(sc, XL_W3_MAC_CTRL, XL_MACCTRL_DUPLEX);
        } else {
                dmsg = "half";
                XL_SEL_WIN(3);
                CSR_WRITE_1(sc, XL_W3_MAC_CTRL,
                        (CSR_READ_1(sc, XL_W3_MAC_CTRL) & ~XL_MACCTRL_DUPLEX));
        }

        if (IFM_SUBTYPE(media) == IFM_10_2)
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_START);
        else
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);

        CSR_WRITE_4(sc, XL_W3_INTERNAL_CFG, icfg);
        XL_SEL_WIN(4);
        CSR_WRITE_2(sc, XL_W4_MEDIA_STATUS, mediastat);

        DELAY(800);
        XL_SEL_WIN(7);

        device_printf(sc->xl_dev, "selecting %s, %s duplex\n", pmsg, dmsg);
}

static void
xl_reset(struct xl_softc *sc)
{
        register int            i;

        XL_LOCK_ASSERT(sc);

        XL_SEL_WIN(0);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RESET |
            ((sc->xl_flags & XL_FLAG_WEIRDRESET) ?
             XL_RESETOPT_DISADVFD:0));

        /*
         * If we're using memory mapped register mode, pause briefly
         * after issuing the reset command before trying to access any
         * other registers. With my 3c575C CardBus card, failing to do
         * this results in the system locking up while trying to poll
         * the command busy bit in the status register.
         */
        if (sc->xl_flags & XL_FLAG_USE_MMIO)
                DELAY(100000);

        for (i = 0; i < XL_TIMEOUT; i++) {
                DELAY(10);
                if (!(CSR_READ_2(sc, XL_STATUS) & XL_STAT_CMDBUSY))
                        break;
        }

        if (i == XL_TIMEOUT)
                device_printf(sc->xl_dev, "reset didn't complete\n");

        /* Reset TX and RX. */
        /* Note: the RX reset takes an absurd amount of time
         * on newer versions of the Tornado chips such as those
         * on the 3c905CX and newer 3c908C cards. We wait an
         * extra amount of time so that xl_wait() doesn't complain
         * and annoy the users.
         */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
        DELAY(100000);
        xl_wait(sc);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
        xl_wait(sc);

        if (sc->xl_flags & XL_FLAG_INVERT_LED_PWR ||
            sc->xl_flags & XL_FLAG_INVERT_MII_PWR) {
                XL_SEL_WIN(2);
                CSR_WRITE_2(sc, XL_W2_RESET_OPTIONS,
                    CSR_READ_2(sc, XL_W2_RESET_OPTIONS) |
                    ((sc->xl_flags & XL_FLAG_INVERT_LED_PWR) ?
                    XL_RESETOPT_INVERT_LED : 0) |
                    ((sc->xl_flags & XL_FLAG_INVERT_MII_PWR) ?
                    XL_RESETOPT_INVERT_MII : 0));
        }

        /* Wait a little while for the chip to get its brains in order. */
        DELAY(100000);
}

/*
 * Probe for a 3Com Etherlink XL chip. Check the PCI vendor and device
 * IDs against our list and return a device name if we find a match.
 */
static int
xl_probe(device_t dev)
{
        const struct xl_type    *t;

        t = xl_devs;

        while (t->xl_name != NULL) {
                if ((pci_get_vendor(dev) == t->xl_vid) &&
                    (pci_get_device(dev) == t->xl_did)) {
                        device_set_desc(dev, t->xl_name);
                        return (BUS_PROBE_DEFAULT);
                }
                t++;
        }

        return (ENXIO);
}

/*
 * This routine is a kludge to work around possible hardware faults
 * or manufacturing defects that can cause the media options register
 * (or reset options register, as it's called for the first generation
 * 3c90x adapters) to return an incorrect result. I have encountered
 * one Dell Latitude laptop docking station with an integrated 3c905-TX
 * which doesn't have any of the 'mediaopt' bits set. This screws up
 * the attach routine pretty badly because it doesn't know what media
 * to look for. If we find ourselves in this predicament, this routine
 * will try to guess the media options values and warn the user of a
 * possible manufacturing defect with his adapter/system/whatever.
 */
static void
xl_mediacheck(struct xl_softc *sc)
{

        /*
         * If some of the media options bits are set, assume they are
         * correct. If not, try to figure it out down below.
         * XXX I should check for 10baseFL, but I don't have an adapter
         * to test with.
         */
        if (sc->xl_media & (XL_MEDIAOPT_MASK & ~XL_MEDIAOPT_VCO)) {
                /*
                 * Check the XCVR value. If it's not in the normal range
                 * of values, we need to fake it up here.
                 */
                if (sc->xl_xcvr <= XL_XCVR_AUTO)
                        return;
                else {
                        device_printf(sc->xl_dev,
                            "bogus xcvr value in EEPROM (%x)\n", sc->xl_xcvr);
                        device_printf(sc->xl_dev,
                            "choosing new default based on card type\n");
                }
        } else {
                if (sc->xl_type == XL_TYPE_905B &&
                    sc->xl_media & XL_MEDIAOPT_10FL)
                        return;
                device_printf(sc->xl_dev,
"WARNING: no media options bits set in the media options register!!\n");
                device_printf(sc->xl_dev,
"this could be a manufacturing defect in your adapter or system\n");
                device_printf(sc->xl_dev,
"attempting to guess media type; you should probably consult your vendor\n");
        }

        xl_choose_xcvr(sc, 1);
}

static void
xl_choose_xcvr(struct xl_softc *sc, int verbose)
{
        u_int16_t               devid;

        /*
         * Read the device ID from the EEPROM.
         * This is what's loaded into the PCI device ID register, so it has
         * to be correct otherwise we wouldn't have gotten this far.
         */
        xl_read_eeprom(sc, (caddr_t)&devid, XL_EE_PRODID, 1, 0);

        switch (devid) {
        case TC_DEVICEID_BOOMERANG_10BT:        /* 3c900-TPO */
        case TC_DEVICEID_KRAKATOA_10BT:         /* 3c900B-TPO */
                sc->xl_media = XL_MEDIAOPT_BT;
                sc->xl_xcvr = XL_XCVR_10BT;
                if (verbose)
                        device_printf(sc->xl_dev,
                            "guessing 10BaseT transceiver\n");
                break;
        case TC_DEVICEID_BOOMERANG_10BT_COMBO:  /* 3c900-COMBO */
        case TC_DEVICEID_KRAKATOA_10BT_COMBO:   /* 3c900B-COMBO */
                sc->xl_media = XL_MEDIAOPT_BT|XL_MEDIAOPT_BNC|XL_MEDIAOPT_AUI;
                sc->xl_xcvr = XL_XCVR_10BT;
                if (verbose)
                        device_printf(sc->xl_dev,
                            "guessing COMBO (AUI/BNC/TP)\n");
                break;
        case TC_DEVICEID_KRAKATOA_10BT_TPC:     /* 3c900B-TPC */
                sc->xl_media = XL_MEDIAOPT_BT|XL_MEDIAOPT_BNC;
                sc->xl_xcvr = XL_XCVR_10BT;
                if (verbose)
                        device_printf(sc->xl_dev, "guessing TPC (BNC/TP)\n");
                break;
        case TC_DEVICEID_CYCLONE_10FL:          /* 3c900B-FL */
                sc->xl_media = XL_MEDIAOPT_10FL;
                sc->xl_xcvr = XL_XCVR_AUI;
                if (verbose)
                        device_printf(sc->xl_dev, "guessing 10baseFL\n");
                break;
        case TC_DEVICEID_BOOMERANG_10_100BT:    /* 3c905-TX */
        case TC_DEVICEID_HURRICANE_555:         /* 3c555 */
        case TC_DEVICEID_HURRICANE_556:         /* 3c556 */
        case TC_DEVICEID_HURRICANE_556B:        /* 3c556B */
        case TC_DEVICEID_HURRICANE_575A:        /* 3c575TX */
        case TC_DEVICEID_HURRICANE_575B:        /* 3c575B */
        case TC_DEVICEID_HURRICANE_575C:        /* 3c575C */
        case TC_DEVICEID_HURRICANE_656:         /* 3c656 */
        case TC_DEVICEID_HURRICANE_656B:        /* 3c656B */
        case TC_DEVICEID_TORNADO_656C:          /* 3c656C */
        case TC_DEVICEID_TORNADO_10_100BT_920B: /* 3c920B-EMB */
        case TC_DEVICEID_TORNADO_10_100BT_920B_WNM:     /* 3c920B-EMB-WNM */
                sc->xl_media = XL_MEDIAOPT_MII;
                sc->xl_xcvr = XL_XCVR_MII;
                if (verbose)
                        device_printf(sc->xl_dev, "guessing MII\n");
                break;
        case TC_DEVICEID_BOOMERANG_100BT4:      /* 3c905-T4 */
        case TC_DEVICEID_CYCLONE_10_100BT4:     /* 3c905B-T4 */
                sc->xl_media = XL_MEDIAOPT_BT4;
                sc->xl_xcvr = XL_XCVR_MII;
                if (verbose)
                        device_printf(sc->xl_dev, "guessing 100baseT4/MII\n");
                break;
        case TC_DEVICEID_HURRICANE_10_100BT:    /* 3c905B-TX */
        case TC_DEVICEID_HURRICANE_10_100BT_SERV:/*3c980-TX */
        case TC_DEVICEID_TORNADO_10_100BT_SERV: /* 3c980C-TX */
        case TC_DEVICEID_HURRICANE_SOHO100TX:   /* 3cSOHO100-TX */
        case TC_DEVICEID_TORNADO_10_100BT:      /* 3c905C-TX */
        case TC_DEVICEID_TORNADO_HOMECONNECT:   /* 3c450-TX */
                sc->xl_media = XL_MEDIAOPT_BTX;
                sc->xl_xcvr = XL_XCVR_AUTO;
                if (verbose)
                        device_printf(sc->xl_dev, "guessing 10/100 internal\n");
                break;
        case TC_DEVICEID_CYCLONE_10_100_COMBO:  /* 3c905B-COMBO */
                sc->xl_media = XL_MEDIAOPT_BTX|XL_MEDIAOPT_BNC|XL_MEDIAOPT_AUI;
                sc->xl_xcvr = XL_XCVR_AUTO;
                if (verbose)
                        device_printf(sc->xl_dev,
                            "guessing 10/100 plus BNC/AUI\n");
                break;
        default:
                device_printf(sc->xl_dev,
                    "unknown device ID: %x -- defaulting to 10baseT\n", devid);
                sc->xl_media = XL_MEDIAOPT_BT;
                break;
        }
}

/*
 * Attach the interface. Allocate softc structures, do ifmedia
 * setup and ethernet/BPF attach.
 */
static int
xl_attach(device_t dev)
{
        u_char                  eaddr[ETHER_ADDR_LEN];
        u_int16_t               sinfo2, xcvr[2];
        struct xl_softc         *sc;
        struct ifnet            *ifp;
        int                     media, pmcap;
        int                     error = 0, phy, rid, res, unit;
        uint16_t                did;

        sc = device_get_softc(dev);
        sc->xl_dev = dev;

        unit = device_get_unit(dev);

        mtx_init(&sc->xl_mtx, device_get_nameunit(dev), MTX_NETWORK_LOCK,
            MTX_DEF);
        ifmedia_init(&sc->ifmedia, 0, xl_ifmedia_upd, xl_ifmedia_sts);

        did = pci_get_device(dev);

        sc->xl_flags = 0;
        if (did == TC_DEVICEID_HURRICANE_555)
                sc->xl_flags |= XL_FLAG_EEPROM_OFFSET_30 | XL_FLAG_PHYOK;
        if (did == TC_DEVICEID_HURRICANE_556 ||
            did == TC_DEVICEID_HURRICANE_556B)
                sc->xl_flags |= XL_FLAG_FUNCREG | XL_FLAG_PHYOK |
                    XL_FLAG_EEPROM_OFFSET_30 | XL_FLAG_WEIRDRESET |
                    XL_FLAG_INVERT_LED_PWR | XL_FLAG_INVERT_MII_PWR;
        if (did == TC_DEVICEID_HURRICANE_555 ||
            did == TC_DEVICEID_HURRICANE_556)
                sc->xl_flags |= XL_FLAG_8BITROM;
        if (did == TC_DEVICEID_HURRICANE_556B)
                sc->xl_flags |= XL_FLAG_NO_XCVR_PWR;

        if (did == TC_DEVICEID_HURRICANE_575B ||
            did == TC_DEVICEID_HURRICANE_575C ||
            did == TC_DEVICEID_HURRICANE_656B ||
            did == TC_DEVICEID_TORNADO_656C)
                sc->xl_flags |= XL_FLAG_FUNCREG;
        if (did == TC_DEVICEID_HURRICANE_575A ||
            did == TC_DEVICEID_HURRICANE_575B ||
            did == TC_DEVICEID_HURRICANE_575C ||
            did == TC_DEVICEID_HURRICANE_656B ||
            did == TC_DEVICEID_TORNADO_656C)
                sc->xl_flags |= XL_FLAG_PHYOK | XL_FLAG_EEPROM_OFFSET_30 |
                  XL_FLAG_8BITROM;
        if (did == TC_DEVICEID_HURRICANE_656)
                sc->xl_flags |= XL_FLAG_FUNCREG | XL_FLAG_PHYOK;
        if (did == TC_DEVICEID_HURRICANE_575B)
                sc->xl_flags |= XL_FLAG_INVERT_LED_PWR;
        if (did == TC_DEVICEID_HURRICANE_575C)
                sc->xl_flags |= XL_FLAG_INVERT_MII_PWR;
        if (did == TC_DEVICEID_TORNADO_656C)
                sc->xl_flags |= XL_FLAG_INVERT_MII_PWR;
        if (did == TC_DEVICEID_HURRICANE_656 ||
            did == TC_DEVICEID_HURRICANE_656B)
                sc->xl_flags |= XL_FLAG_INVERT_MII_PWR |
                    XL_FLAG_INVERT_LED_PWR;
        if (did == TC_DEVICEID_TORNADO_10_100BT_920B ||
            did == TC_DEVICEID_TORNADO_10_100BT_920B_WNM)
                sc->xl_flags |= XL_FLAG_PHYOK;

        switch (did) {
        case TC_DEVICEID_BOOMERANG_10_100BT:    /* 3c905-TX */
        case TC_DEVICEID_HURRICANE_575A:
        case TC_DEVICEID_HURRICANE_575B:
        case TC_DEVICEID_HURRICANE_575C:
                sc->xl_flags |= XL_FLAG_NO_MMIO;
                break;
        default:
                break;
        }

        /*
         * Map control/status registers.
         */
        pci_enable_busmaster(dev);

        if ((sc->xl_flags & XL_FLAG_NO_MMIO) == 0) {
                rid = XL_PCI_LOMEM;
                res = SYS_RES_MEMORY;

                sc->xl_res = bus_alloc_resource_any(dev, res, &rid, RF_ACTIVE);
        }

        if (sc->xl_res != NULL) {
                sc->xl_flags |= XL_FLAG_USE_MMIO;
                if (bootverbose)
                        device_printf(dev, "using memory mapped I/O\n");
        } else {
                rid = XL_PCI_LOIO;
                res = SYS_RES_IOPORT;
                sc->xl_res = bus_alloc_resource_any(dev, res, &rid, RF_ACTIVE);
                if (sc->xl_res == NULL) {
                        device_printf(dev, "couldn't map ports/memory\n");
                        error = ENXIO;
                        goto fail;
                }
                if (bootverbose)
                        device_printf(dev, "using port I/O\n");
        }

        sc->xl_btag = rman_get_bustag(sc->xl_res);
        sc->xl_bhandle = rman_get_bushandle(sc->xl_res);

        if (sc->xl_flags & XL_FLAG_FUNCREG) {
                rid = XL_PCI_FUNCMEM;
                sc->xl_fres = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
                    RF_ACTIVE);

                if (sc->xl_fres == NULL) {
                        device_printf(dev, "couldn't map funcreg memory\n");
                        error = ENXIO;
                        goto fail;
                }

                sc->xl_ftag = rman_get_bustag(sc->xl_fres);
                sc->xl_fhandle = rman_get_bushandle(sc->xl_fres);
        }

        /* Allocate interrupt */
        rid = 0;
        sc->xl_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
            RF_SHAREABLE | RF_ACTIVE);
        if (sc->xl_irq == NULL) {
                device_printf(dev, "couldn't map interrupt\n");
                error = ENXIO;
                goto fail;
        }

        /* Initialize interface name. */
        ifp = sc->xl_ifp = if_alloc(IFT_ETHER);
        if (ifp == NULL) {
                device_printf(dev, "can not if_alloc()\n");
                error = ENOSPC;
                goto fail;
        }
        ifp->if_softc = sc;
        if_initname(ifp, device_get_name(dev), device_get_unit(dev));

        /* Reset the adapter. */
        XL_LOCK(sc);
        xl_reset(sc);
        XL_UNLOCK(sc);

        /*
         * Get station address from the EEPROM.
         */
        if (xl_read_eeprom(sc, (caddr_t)&eaddr, XL_EE_OEM_ADR0, 3, 1)) {
                device_printf(dev, "failed to read station address\n");
                error = ENXIO;
                goto fail;
        }

        callout_init_mtx(&sc->xl_tick_callout, &sc->xl_mtx, 0);
        TASK_INIT(&sc->xl_task, 0, xl_rxeof_task, sc);

        /*
         * Now allocate a tag for the DMA descriptor lists and a chunk
         * of DMA-able memory based on the tag.  Also obtain the DMA
         * addresses of the RX and TX ring, which we'll need later.
         * All of our lists are allocated as a contiguous block
         * of memory.
         */
        error = bus_dma_tag_create(bus_get_dma_tag(dev), 8, 0,
            BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
            XL_RX_LIST_SZ, 1, XL_RX_LIST_SZ, 0, NULL, NULL,
            &sc->xl_ldata.xl_rx_tag);
        if (error) {
                device_printf(dev, "failed to allocate rx dma tag\n");
                goto fail;
        }

        error = bus_dmamem_alloc(sc->xl_ldata.xl_rx_tag,
            (void **)&sc->xl_ldata.xl_rx_list, BUS_DMA_NOWAIT |
            BUS_DMA_COHERENT | BUS_DMA_ZERO, &sc->xl_ldata.xl_rx_dmamap);
        if (error) {
                device_printf(dev, "no memory for rx list buffers!\n");
                bus_dma_tag_destroy(sc->xl_ldata.xl_rx_tag);
                sc->xl_ldata.xl_rx_tag = NULL;
                goto fail;
        }

        error = bus_dmamap_load(sc->xl_ldata.xl_rx_tag,
            sc->xl_ldata.xl_rx_dmamap, sc->xl_ldata.xl_rx_list,
            XL_RX_LIST_SZ, xl_dma_map_addr,
            &sc->xl_ldata.xl_rx_dmaaddr, BUS_DMA_NOWAIT);
        if (error) {
                device_printf(dev, "cannot get dma address of the rx ring!\n");
                bus_dmamem_free(sc->xl_ldata.xl_rx_tag, sc->xl_ldata.xl_rx_list,
                    sc->xl_ldata.xl_rx_dmamap);
                bus_dma_tag_destroy(sc->xl_ldata.xl_rx_tag);
                sc->xl_ldata.xl_rx_tag = NULL;
                goto fail;
        }

        error = bus_dma_tag_create(bus_get_dma_tag(dev), 8, 0,
            BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
            XL_TX_LIST_SZ, 1, XL_TX_LIST_SZ, 0, NULL, NULL,
            &sc->xl_ldata.xl_tx_tag);
        if (error) {
                device_printf(dev, "failed to allocate tx dma tag\n");
                goto fail;
        }

        error = bus_dmamem_alloc(sc->xl_ldata.xl_tx_tag,
            (void **)&sc->xl_ldata.xl_tx_list, BUS_DMA_NOWAIT |
            BUS_DMA_COHERENT | BUS_DMA_ZERO, &sc->xl_ldata.xl_tx_dmamap);
        if (error) {
                device_printf(dev, "no memory for list buffers!\n");
                bus_dma_tag_destroy(sc->xl_ldata.xl_tx_tag);
                sc->xl_ldata.xl_tx_tag = NULL;
                goto fail;
        }

        error = bus_dmamap_load(sc->xl_ldata.xl_tx_tag,
            sc->xl_ldata.xl_tx_dmamap, sc->xl_ldata.xl_tx_list,
            XL_TX_LIST_SZ, xl_dma_map_addr,
            &sc->xl_ldata.xl_tx_dmaaddr, BUS_DMA_NOWAIT);
        if (error) {
                device_printf(dev, "cannot get dma address of the tx ring!\n");
                bus_dmamem_free(sc->xl_ldata.xl_tx_tag, sc->xl_ldata.xl_tx_list,
                    sc->xl_ldata.xl_tx_dmamap);
                bus_dma_tag_destroy(sc->xl_ldata.xl_tx_tag);
                sc->xl_ldata.xl_tx_tag = NULL;
                goto fail;
        }

        /*
         * Allocate a DMA tag for the mapping of mbufs.
         */
        error = bus_dma_tag_create(bus_get_dma_tag(dev), 1, 0,
            BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
            MCLBYTES * XL_MAXFRAGS, XL_MAXFRAGS, MCLBYTES, 0, NULL,
            NULL, &sc->xl_mtag);
        if (error) {
                device_printf(dev, "failed to allocate mbuf dma tag\n");
                goto fail;
        }

        /* We need a spare DMA map for the RX ring. */
        error = bus_dmamap_create(sc->xl_mtag, 0, &sc->xl_tmpmap);
        if (error)
                goto fail;

        /*
         * Figure out the card type. 3c905B adapters have the
         * 'supportsNoTxLength' bit set in the capabilities
         * word in the EEPROM.
         * Note: my 3c575C CardBus card lies. It returns a value
         * of 0x1578 for its capabilities word, which is somewhat
         * nonsensical. Another way to distinguish a 3c90x chip
         * from a 3c90xB/C chip is to check for the 'supportsLargePackets'
         * bit. This will only be set for 3c90x boomerage chips.
         */
        xl_read_eeprom(sc, (caddr_t)&sc->xl_caps, XL_EE_CAPS, 1, 0);
        if (sc->xl_caps & XL_CAPS_NO_TXLENGTH ||
            !(sc->xl_caps & XL_CAPS_LARGE_PKTS))
                sc->xl_type = XL_TYPE_905B;
        else
                sc->xl_type = XL_TYPE_90X;

        /* Check availability of WOL. */
        if ((sc->xl_caps & XL_CAPS_PWRMGMT) != 0 &&
            pci_find_cap(dev, PCIY_PMG, &pmcap) == 0) {
                sc->xl_pmcap = pmcap;
                sc->xl_flags |= XL_FLAG_WOL;
                sinfo2 = 0;
                xl_read_eeprom(sc, (caddr_t)&sinfo2, XL_EE_SOFTINFO2, 1, 0);
                if ((sinfo2 & XL_SINFO2_AUX_WOL_CON) == 0 && bootverbose)
                        device_printf(dev,
                            "No auxiliary remote wakeup connector!\n");
        }

        /* Set the TX start threshold for best performance. */
        sc->xl_tx_thresh = XL_MIN_FRAMELEN;

        ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
        ifp->if_ioctl = xl_ioctl;
        ifp->if_capabilities = IFCAP_VLAN_MTU;
        if (sc->xl_type == XL_TYPE_905B) {
                ifp->if_hwassist = XL905B_CSUM_FEATURES;
#ifdef XL905B_TXCSUM_BROKEN
                ifp->if_capabilities |= IFCAP_RXCSUM;
#else
                ifp->if_capabilities |= IFCAP_HWCSUM;
#endif
        }
        if ((sc->xl_flags & XL_FLAG_WOL) != 0)
                ifp->if_capabilities |= IFCAP_WOL_MAGIC;
        ifp->if_capenable = ifp->if_capabilities;
#ifdef DEVICE_POLLING
        ifp->if_capabilities |= IFCAP_POLLING;
#endif
        ifp->if_start = xl_start;
        ifp->if_init = xl_init;
        IFQ_SET_MAXLEN(&ifp->if_snd, XL_TX_LIST_CNT - 1);
        ifp->if_snd.ifq_drv_maxlen = XL_TX_LIST_CNT - 1;
        IFQ_SET_READY(&ifp->if_snd);

        /*
         * Now we have to see what sort of media we have.
         * This includes probing for an MII interace and a
         * possible PHY.
         */
        XL_SEL_WIN(3);
        sc->xl_media = CSR_READ_2(sc, XL_W3_MEDIA_OPT);
        if (bootverbose)
                device_printf(dev, "media options word: %x\n", sc->xl_media);

        xl_read_eeprom(sc, (char *)&xcvr, XL_EE_ICFG_0, 2, 0);
        sc->xl_xcvr = xcvr[0] | xcvr[1] << 16;
        sc->xl_xcvr &= XL_ICFG_CONNECTOR_MASK;
        sc->xl_xcvr >>= XL_ICFG_CONNECTOR_BITS;

        xl_mediacheck(sc);

        if (sc->xl_media & XL_MEDIAOPT_MII ||
            sc->xl_media & XL_MEDIAOPT_BTX ||
            sc->xl_media & XL_MEDIAOPT_BT4) {
                if (bootverbose)
                        device_printf(dev, "found MII/AUTO\n");
                xl_setcfg(sc);
                /*
                 * Attach PHYs only at MII address 24 if !XL_FLAG_PHYOK.
                 * This is to guard against problems with certain 3Com ASIC
                 * revisions that incorrectly map the internal transceiver
                 * control registers at all MII addresses.
                 */
                phy = MII_PHY_ANY;
                if ((sc->xl_flags & XL_FLAG_PHYOK) == 0)
                        phy = 24;
                error = mii_attach(dev, &sc->xl_miibus, ifp, xl_ifmedia_upd,
                    xl_ifmedia_sts, BMSR_DEFCAPMASK, phy, MII_OFFSET_ANY,
                    sc->xl_type == XL_TYPE_905B ? MIIF_DOPAUSE : 0);
                if (error != 0) {
                        device_printf(dev, "attaching PHYs failed\n");
                        goto fail;
                }
                goto done;
        }

        /*
         * Sanity check. If the user has selected "auto" and this isn't
         * a 10/100 card of some kind, we need to force the transceiver
         * type to something sane.
         */
        if (sc->xl_xcvr == XL_XCVR_AUTO)
                xl_choose_xcvr(sc, bootverbose);

        /*
         * Do ifmedia setup.
         */
        if (sc->xl_media & XL_MEDIAOPT_BT) {
                if (bootverbose)
                        device_printf(dev, "found 10baseT\n");
                ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_T, 0, NULL);
                ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_T|IFM_HDX, 0, NULL);
                if (sc->xl_caps & XL_CAPS_FULL_DUPLEX)
                        ifmedia_add(&sc->ifmedia,
                            IFM_ETHER|IFM_10_T|IFM_FDX, 0, NULL);
        }

        if (sc->xl_media & (XL_MEDIAOPT_AUI|XL_MEDIAOPT_10FL)) {
                /*
                 * Check for a 10baseFL board in disguise.
                 */
                if (sc->xl_type == XL_TYPE_905B &&
                    sc->xl_media == XL_MEDIAOPT_10FL) {
                        if (bootverbose)
                                device_printf(dev, "found 10baseFL\n");
                        ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_FL, 0, NULL);
                        ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_FL|IFM_HDX,
                            0, NULL);
                        if (sc->xl_caps & XL_CAPS_FULL_DUPLEX)
                                ifmedia_add(&sc->ifmedia,
                                    IFM_ETHER|IFM_10_FL|IFM_FDX, 0, NULL);
                } else {
                        if (bootverbose)
                                device_printf(dev, "found AUI\n");
                        ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_5, 0, NULL);
                }
        }

        if (sc->xl_media & XL_MEDIAOPT_BNC) {
                if (bootverbose)
                        device_printf(dev, "found BNC\n");
                ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_10_2, 0, NULL);
        }

        if (sc->xl_media & XL_MEDIAOPT_BFX) {
                if (bootverbose)
                        device_printf(dev, "found 100baseFX\n");
                ifmedia_add(&sc->ifmedia, IFM_ETHER|IFM_100_FX, 0, NULL);
        }

        media = IFM_ETHER|IFM_100_TX|IFM_FDX;
        xl_choose_media(sc, &media);

        if (sc->xl_miibus == NULL)
                ifmedia_set(&sc->ifmedia, media);

done:
        if (sc->xl_flags & XL_FLAG_NO_XCVR_PWR) {
                XL_SEL_WIN(0);
                CSR_WRITE_2(sc, XL_W0_MFG_ID, XL_NO_XCVR_PWR_MAGICBITS);
        }

        /*
         * Call MI attach routine.
         */
        ether_ifattach(ifp, eaddr);

        error = bus_setup_intr(dev, sc->xl_irq, INTR_TYPE_NET | INTR_MPSAFE,
            NULL, xl_intr, sc, &sc->xl_intrhand);
        if (error) {
                device_printf(dev, "couldn't set up irq\n");
                ether_ifdetach(ifp);
                goto fail;
        }

fail:
        if (error)
                xl_detach(dev);

        return (error);
}

/*
 * Choose a default media.
 * XXX This is a leaf function only called by xl_attach() and
 *     acquires/releases the non-recursible driver mutex to
 *     satisfy lock assertions.
 */
static void
xl_choose_media(struct xl_softc *sc, int *media)
{

        XL_LOCK(sc);

        switch (sc->xl_xcvr) {
        case XL_XCVR_10BT:
                *media = IFM_ETHER|IFM_10_T;
                xl_setmode(sc, *media);
                break;
        case XL_XCVR_AUI:
                if (sc->xl_type == XL_TYPE_905B &&
                    sc->xl_media == XL_MEDIAOPT_10FL) {
                        *media = IFM_ETHER|IFM_10_FL;
                        xl_setmode(sc, *media);
                } else {
                        *media = IFM_ETHER|IFM_10_5;
                        xl_setmode(sc, *media);
                }
                break;
        case XL_XCVR_COAX:
                *media = IFM_ETHER|IFM_10_2;
                xl_setmode(sc, *media);
                break;
        case XL_XCVR_AUTO:
        case XL_XCVR_100BTX:
        case XL_XCVR_MII:
                /* Chosen by miibus */
                break;
        case XL_XCVR_100BFX:
                *media = IFM_ETHER|IFM_100_FX;
                break;
        default:
                device_printf(sc->xl_dev, "unknown XCVR type: %d\n",
                    sc->xl_xcvr);
                /*
                 * This will probably be wrong, but it prevents
                 * the ifmedia code from panicking.
                 */
                *media = IFM_ETHER|IFM_10_T;
                break;
        }

        XL_UNLOCK(sc);
}

/*
 * Shutdown hardware and free up resources. This can be called any
 * time after the mutex has been initialized. It is called in both
 * the error case in attach and the normal detach case so it needs
 * to be careful about only freeing resources that have actually been
 * allocated.
 */
static int
xl_detach(device_t dev)
{
        struct xl_softc         *sc;
        struct ifnet            *ifp;
        int                     rid, res;

        sc = device_get_softc(dev);
        ifp = sc->xl_ifp;

        KASSERT(mtx_initialized(&sc->xl_mtx), ("xl mutex not initialized"));

#ifdef DEVICE_POLLING
        if (ifp && ifp->if_capenable & IFCAP_POLLING)
                ether_poll_deregister(ifp);
#endif

        if (sc->xl_flags & XL_FLAG_USE_MMIO) {
                rid = XL_PCI_LOMEM;
                res = SYS_RES_MEMORY;
        } else {
                rid = XL_PCI_LOIO;
                res = SYS_RES_IOPORT;
        }

        /* These should only be active if attach succeeded */
        if (device_is_attached(dev)) {
                XL_LOCK(sc);
                xl_stop(sc);
                XL_UNLOCK(sc);
                taskqueue_drain(taskqueue_swi, &sc->xl_task);
                callout_drain(&sc->xl_tick_callout);
                ether_ifdetach(ifp);
        }
        if (sc->xl_miibus)
                device_delete_child(dev, sc->xl_miibus);
        bus_generic_detach(dev);
        ifmedia_removeall(&sc->ifmedia);

        if (sc->xl_intrhand)
                bus_teardown_intr(dev, sc->xl_irq, sc->xl_intrhand);
        if (sc->xl_irq)
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->xl_irq);
        if (sc->xl_fres != NULL)
                bus_release_resource(dev, SYS_RES_MEMORY,
                    XL_PCI_FUNCMEM, sc->xl_fres);
        if (sc->xl_res)
                bus_release_resource(dev, res, rid, sc->xl_res);

        if (ifp)
                if_free(ifp);

        if (sc->xl_mtag) {
                bus_dmamap_destroy(sc->xl_mtag, sc->xl_tmpmap);
                bus_dma_tag_destroy(sc->xl_mtag);
        }
        if (sc->xl_ldata.xl_rx_tag) {
                bus_dmamap_unload(sc->xl_ldata.xl_rx_tag,
                    sc->xl_ldata.xl_rx_dmamap);
                bus_dmamem_free(sc->xl_ldata.xl_rx_tag, sc->xl_ldata.xl_rx_list,
                    sc->xl_ldata.xl_rx_dmamap);
                bus_dma_tag_destroy(sc->xl_ldata.xl_rx_tag);
        }
        if (sc->xl_ldata.xl_tx_tag) {
                bus_dmamap_unload(sc->xl_ldata.xl_tx_tag,
                    sc->xl_ldata.xl_tx_dmamap);
                bus_dmamem_free(sc->xl_ldata.xl_tx_tag, sc->xl_ldata.xl_tx_list,
                    sc->xl_ldata.xl_tx_dmamap);
                bus_dma_tag_destroy(sc->xl_ldata.xl_tx_tag);
        }

        mtx_destroy(&sc->xl_mtx);

        return (0);
}

/*
 * Initialize the transmit descriptors.
 */
static int
xl_list_tx_init(struct xl_softc *sc)
{
        struct xl_chain_data    *cd;
        struct xl_list_data     *ld;
        int                     error, i;

        XL_LOCK_ASSERT(sc);

        cd = &sc->xl_cdata;
        ld = &sc->xl_ldata;
        for (i = 0; i < XL_TX_LIST_CNT; i++) {
                cd->xl_tx_chain[i].xl_ptr = &ld->xl_tx_list[i];
                error = bus_dmamap_create(sc->xl_mtag, 0,
                    &cd->xl_tx_chain[i].xl_map);
                if (error)
                        return (error);
                cd->xl_tx_chain[i].xl_phys = ld->xl_tx_dmaaddr +
                    i * sizeof(struct xl_list);
                if (i == (XL_TX_LIST_CNT - 1))
                        cd->xl_tx_chain[i].xl_next = NULL;
                else
                        cd->xl_tx_chain[i].xl_next = &cd->xl_tx_chain[i + 1];
        }

        cd->xl_tx_free = &cd->xl_tx_chain[0];
        cd->xl_tx_tail = cd->xl_tx_head = NULL;

        bus_dmamap_sync(ld->xl_tx_tag, ld->xl_tx_dmamap, BUS_DMASYNC_PREWRITE);
        return (0);
}

/*
 * Initialize the transmit descriptors.
 */
static int
xl_list_tx_init_90xB(struct xl_softc *sc)
{
        struct xl_chain_data    *cd;
        struct xl_list_data     *ld;
        int                     error, i;

        XL_LOCK_ASSERT(sc);

        cd = &sc->xl_cdata;
        ld = &sc->xl_ldata;
        for (i = 0; i < XL_TX_LIST_CNT; i++) {
                cd->xl_tx_chain[i].xl_ptr = &ld->xl_tx_list[i];
                error = bus_dmamap_create(sc->xl_mtag, 0,
                    &cd->xl_tx_chain[i].xl_map);
                if (error)
                        return (error);
                cd->xl_tx_chain[i].xl_phys = ld->xl_tx_dmaaddr +
                    i * sizeof(struct xl_list);
                if (i == (XL_TX_LIST_CNT - 1))
                        cd->xl_tx_chain[i].xl_next = &cd->xl_tx_chain[0];
                else
                        cd->xl_tx_chain[i].xl_next = &cd->xl_tx_chain[i + 1];
                if (i == 0)
                        cd->xl_tx_chain[i].xl_prev =
                            &cd->xl_tx_chain[XL_TX_LIST_CNT - 1];
                else
                        cd->xl_tx_chain[i].xl_prev =
                            &cd->xl_tx_chain[i - 1];
        }

        bzero(ld->xl_tx_list, XL_TX_LIST_SZ);
        ld->xl_tx_list[0].xl_status = htole32(XL_TXSTAT_EMPTY);

        cd->xl_tx_prod = 1;
        cd->xl_tx_cons = 1;
        cd->xl_tx_cnt = 0;

        bus_dmamap_sync(ld->xl_tx_tag, ld->xl_tx_dmamap, BUS_DMASYNC_PREWRITE);
        return (0);
}

/*
 * Initialize the RX descriptors and allocate mbufs for them. Note that
 * we arrange the descriptors in a closed ring, so that the last descriptor
 * points back to the first.
 */
static int
xl_list_rx_init(struct xl_softc *sc)
{
        struct xl_chain_data    *cd;
        struct xl_list_data     *ld;
        int                     error, i, next;
        u_int32_t               nextptr;

        XL_LOCK_ASSERT(sc);

        cd = &sc->xl_cdata;
        ld = &sc->xl_ldata;

        for (i = 0; i < XL_RX_LIST_CNT; i++) {
                cd->xl_rx_chain[i].xl_ptr = &ld->xl_rx_list[i];
                error = bus_dmamap_create(sc->xl_mtag, 0,
                    &cd->xl_rx_chain[i].xl_map);
                if (error)
                        return (error);
                error = xl_newbuf(sc, &cd->xl_rx_chain[i]);
                if (error)
                        return (error);
                if (i == (XL_RX_LIST_CNT - 1))
                        next = 0;
                else
                        next = i + 1;
                nextptr = ld->xl_rx_dmaaddr +
                    next * sizeof(struct xl_list_onefrag);
                cd->xl_rx_chain[i].xl_next = &cd->xl_rx_chain[next];
                ld->xl_rx_list[i].xl_next = htole32(nextptr);
        }

        bus_dmamap_sync(ld->xl_rx_tag, ld->xl_rx_dmamap, BUS_DMASYNC_PREWRITE);
        cd->xl_rx_head = &cd->xl_rx_chain[0];

        return (0);
}

/*
 * Initialize an RX descriptor and attach an MBUF cluster.
 * If we fail to do so, we need to leave the old mbuf and
 * the old DMA map untouched so that it can be reused.
 */
static int
xl_newbuf(struct xl_softc *sc, struct xl_chain_onefrag *c)
{
        struct mbuf             *m_new = NULL;
        bus_dmamap_t            map;
        bus_dma_segment_t       segs[1];
        int                     error, nseg;

        XL_LOCK_ASSERT(sc);

        m_new = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
        if (m_new == NULL)
                return (ENOBUFS);

        m_new->m_len = m_new->m_pkthdr.len = MCLBYTES;

        /* Force longword alignment for packet payload. */
        m_adj(m_new, ETHER_ALIGN);

        error = bus_dmamap_load_mbuf_sg(sc->xl_mtag, sc->xl_tmpmap, m_new,
            segs, &nseg, BUS_DMA_NOWAIT);
        if (error) {
                m_freem(m_new);
                device_printf(sc->xl_dev, "can't map mbuf (error %d)\n",
                    error);
                return (error);
        }
        KASSERT(nseg == 1,
            ("%s: too many DMA segments (%d)", __func__, nseg));

        bus_dmamap_unload(sc->xl_mtag, c->xl_map);
        map = c->xl_map;
        c->xl_map = sc->xl_tmpmap;
        sc->xl_tmpmap = map;
        c->xl_mbuf = m_new;
        c->xl_ptr->xl_frag.xl_len = htole32(m_new->m_len | XL_LAST_FRAG);
        c->xl_ptr->xl_frag.xl_addr = htole32(segs->ds_addr);
        c->xl_ptr->xl_status = 0;
        bus_dmamap_sync(sc->xl_mtag, c->xl_map, BUS_DMASYNC_PREREAD);
        return (0);
}

static int
xl_rx_resync(struct xl_softc *sc)
{
        struct xl_chain_onefrag *pos;
        int                     i;

        XL_LOCK_ASSERT(sc);

        pos = sc->xl_cdata.xl_rx_head;

        for (i = 0; i < XL_RX_LIST_CNT; i++) {
                if (pos->xl_ptr->xl_status)
                        break;
                pos = pos->xl_next;
        }

        if (i == XL_RX_LIST_CNT)
                return (0);

        sc->xl_cdata.xl_rx_head = pos;

        return (EAGAIN);
}

/*
 * A frame has been uploaded: pass the resulting mbuf chain up to
 * the higher level protocols.
 */
static int
xl_rxeof(struct xl_softc *sc)
{
        struct mbuf             *m;
        struct ifnet            *ifp = sc->xl_ifp;
        struct xl_chain_onefrag *cur_rx;
        int                     total_len;
        int                     rx_npkts = 0;
        u_int32_t               rxstat;

        XL_LOCK_ASSERT(sc);
again:
        bus_dmamap_sync(sc->xl_ldata.xl_rx_tag, sc->xl_ldata.xl_rx_dmamap,
            BUS_DMASYNC_POSTREAD);
        while ((rxstat = le32toh(sc->xl_cdata.xl_rx_head->xl_ptr->xl_status))) {
#ifdef DEVICE_POLLING
                if (ifp->if_capenable & IFCAP_POLLING) {
                        if (sc->rxcycles <= 0)
                                break;
                        sc->rxcycles--;
                }
#endif
                cur_rx = sc->xl_cdata.xl_rx_head;
                sc->xl_cdata.xl_rx_head = cur_rx->xl_next;
                total_len = rxstat & XL_RXSTAT_LENMASK;
                rx_npkts++;

                /*
                 * Since we have told the chip to allow large frames,
                 * we need to trap giant frame errors in software. We allow
                 * a little more than the normal frame size to account for
                 * frames with VLAN tags.
                 */
                if (total_len > XL_MAX_FRAMELEN)
                        rxstat |= (XL_RXSTAT_UP_ERROR|XL_RXSTAT_OVERSIZE);

                /*
                 * If an error occurs, update stats, clear the
                 * status word and leave the mbuf cluster in place:
                 * it should simply get re-used next time this descriptor
                 * comes up in the ring.
                 */
                if (rxstat & XL_RXSTAT_UP_ERROR) {
                        if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
                        cur_rx->xl_ptr->xl_status = 0;
                        bus_dmamap_sync(sc->xl_ldata.xl_rx_tag,
                            sc->xl_ldata.xl_rx_dmamap, BUS_DMASYNC_PREWRITE);
                        continue;
                }

                /*
                 * If the error bit was not set, the upload complete
                 * bit should be set which means we have a valid packet.
                 * If not, something truly strange has happened.
                 */
                if (!(rxstat & XL_RXSTAT_UP_CMPLT)) {
                        device_printf(sc->xl_dev,
                            "bad receive status -- packet dropped\n");
                        if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
                        cur_rx->xl_ptr->xl_status = 0;
                        bus_dmamap_sync(sc->xl_ldata.xl_rx_tag,
                            sc->xl_ldata.xl_rx_dmamap, BUS_DMASYNC_PREWRITE);
                        continue;
                }

                /* No errors; receive the packet. */
                bus_dmamap_sync(sc->xl_mtag, cur_rx->xl_map,
                    BUS_DMASYNC_POSTREAD);
                m = cur_rx->xl_mbuf;

                /*
                 * Try to conjure up a new mbuf cluster. If that
                 * fails, it means we have an out of memory condition and
                 * should leave the buffer in place and continue. This will
                 * result in a lost packet, but there's little else we
                 * can do in this situation.
                 */
                if (xl_newbuf(sc, cur_rx)) {
                        if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
                        cur_rx->xl_ptr->xl_status = 0;
                        bus_dmamap_sync(sc->xl_ldata.xl_rx_tag,
                            sc->xl_ldata.xl_rx_dmamap, BUS_DMASYNC_PREWRITE);
                        continue;
                }
                bus_dmamap_sync(sc->xl_ldata.xl_rx_tag,
                    sc->xl_ldata.xl_rx_dmamap, BUS_DMASYNC_PREWRITE);

                if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
                m->m_pkthdr.rcvif = ifp;
                m->m_pkthdr.len = m->m_len = total_len;

                if (ifp->if_capenable & IFCAP_RXCSUM) {
                        /* Do IP checksum checking. */
                        if (rxstat & XL_RXSTAT_IPCKOK)
                                m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED;
                        if (!(rxstat & XL_RXSTAT_IPCKERR))
                                m->m_pkthdr.csum_flags |= CSUM_IP_VALID;
                        if ((rxstat & XL_RXSTAT_TCPCOK &&
                             !(rxstat & XL_RXSTAT_TCPCKERR)) ||
                            (rxstat & XL_RXSTAT_UDPCKOK &&
                             !(rxstat & XL_RXSTAT_UDPCKERR))) {
                                m->m_pkthdr.csum_flags |=
                                        CSUM_DATA_VALID|CSUM_PSEUDO_HDR;
                                m->m_pkthdr.csum_data = 0xffff;
                        }
                }

                XL_UNLOCK(sc);
                (*ifp->if_input)(ifp, m);
                XL_LOCK(sc);

                /*
                 * If we are running from the taskqueue, the interface
                 * might have been stopped while we were passing the last
                 * packet up the network stack.
                 */
                if (!(ifp->if_drv_flags & IFF_DRV_RUNNING))
                        return (rx_npkts);
        }

        /*
         * Handle the 'end of channel' condition. When the upload
         * engine hits the end of the RX ring, it will stall. This
         * is our cue to flush the RX ring, reload the uplist pointer
         * register and unstall the engine.
         * XXX This is actually a little goofy. With the ThunderLAN
         * chip, you get an interrupt when the receiver hits the end
         * of the receive ring, which tells you exactly when you
         * you need to reload the ring pointer. Here we have to
         * fake it. I'm mad at myself for not being clever enough
         * to avoid the use of a goto here.
         */
        if (CSR_READ_4(sc, XL_UPLIST_PTR) == 0 ||
                CSR_READ_4(sc, XL_UPLIST_STATUS) & XL_PKTSTAT_UP_STALLED) {
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_STALL);
                xl_wait(sc);
                CSR_WRITE_4(sc, XL_UPLIST_PTR, sc->xl_ldata.xl_rx_dmaaddr);
                sc->xl_cdata.xl_rx_head = &sc->xl_cdata.xl_rx_chain[0];
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_UNSTALL);
                goto again;
        }
        return (rx_npkts);
}

/*
 * Taskqueue wrapper for xl_rxeof().
 */
static void
xl_rxeof_task(void *arg, int pending)
{
        struct xl_softc *sc = (struct xl_softc *)arg;

        XL_LOCK(sc);
        if (sc->xl_ifp->if_drv_flags & IFF_DRV_RUNNING)
                xl_rxeof(sc);
        XL_UNLOCK(sc);
}

/*
 * A frame was downloaded to the chip. It's safe for us to clean up
 * the list buffers.
 */
static void
xl_txeof(struct xl_softc *sc)
{
        struct xl_chain         *cur_tx;
        struct ifnet            *ifp = sc->xl_ifp;

        XL_LOCK_ASSERT(sc);

        /*
         * Go through our tx list and free mbufs for those
         * frames that have been uploaded. Note: the 3c905B
         * sets a special bit in the status word to let us
         * know that a frame has been downloaded, but the
         * original 3c900/3c905 adapters don't do that.
         * Consequently, we have to use a different test if
         * xl_type != XL_TYPE_905B.
         */
        while (sc->xl_cdata.xl_tx_head != NULL) {
                cur_tx = sc->xl_cdata.xl_tx_head;

                if (CSR_READ_4(sc, XL_DOWNLIST_PTR))
                        break;

                sc->xl_cdata.xl_tx_head = cur_tx->xl_next;
                bus_dmamap_sync(sc->xl_mtag, cur_tx->xl_map,
                    BUS_DMASYNC_POSTWRITE);
                bus_dmamap_unload(sc->xl_mtag, cur_tx->xl_map);
                m_freem(cur_tx->xl_mbuf);
                cur_tx->xl_mbuf = NULL;
                if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
                ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;

                cur_tx->xl_next = sc->xl_cdata.xl_tx_free;
                sc->xl_cdata.xl_tx_free = cur_tx;
        }

        if (sc->xl_cdata.xl_tx_head == NULL) {
                sc->xl_wdog_timer = 0;
                sc->xl_cdata.xl_tx_tail = NULL;
        } else {
                if (CSR_READ_4(sc, XL_DMACTL) & XL_DMACTL_DOWN_STALLED ||
                        !CSR_READ_4(sc, XL_DOWNLIST_PTR)) {
                        CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                                sc->xl_cdata.xl_tx_head->xl_phys);
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                }
        }
}

static void
xl_txeof_90xB(struct xl_softc *sc)
{
        struct xl_chain         *cur_tx = NULL;
        struct ifnet            *ifp = sc->xl_ifp;
        int                     idx;

        XL_LOCK_ASSERT(sc);

        bus_dmamap_sync(sc->xl_ldata.xl_tx_tag, sc->xl_ldata.xl_tx_dmamap,
            BUS_DMASYNC_POSTREAD);
        idx = sc->xl_cdata.xl_tx_cons;
        while (idx != sc->xl_cdata.xl_tx_prod) {
                cur_tx = &sc->xl_cdata.xl_tx_chain[idx];

                if (!(le32toh(cur_tx->xl_ptr->xl_status) &
                      XL_TXSTAT_DL_COMPLETE))
                        break;

                if (cur_tx->xl_mbuf != NULL) {
                        bus_dmamap_sync(sc->xl_mtag, cur_tx->xl_map,
                            BUS_DMASYNC_POSTWRITE);
                        bus_dmamap_unload(sc->xl_mtag, cur_tx->xl_map);
                        m_freem(cur_tx->xl_mbuf);
                        cur_tx->xl_mbuf = NULL;
                }

                if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);

                sc->xl_cdata.xl_tx_cnt--;
                XL_INC(idx, XL_TX_LIST_CNT);
        }

        if (sc->xl_cdata.xl_tx_cnt == 0)
                sc->xl_wdog_timer = 0;
        sc->xl_cdata.xl_tx_cons = idx;

        if (cur_tx != NULL)
                ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
}

/*
 * TX 'end of channel' interrupt handler. Actually, we should
 * only get a 'TX complete' interrupt if there's a transmit error,
 * so this is really TX error handler.
 */
static void
xl_txeoc(struct xl_softc *sc)
{
        u_int8_t                txstat;

        XL_LOCK_ASSERT(sc);

        while ((txstat = CSR_READ_1(sc, XL_TX_STATUS))) {
                if (txstat & XL_TXSTATUS_UNDERRUN ||
                        txstat & XL_TXSTATUS_JABBER ||
                        txstat & XL_TXSTATUS_RECLAIM) {
                        device_printf(sc->xl_dev,
                            "transmission error: 0x%02x\n", txstat);
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
                        xl_wait(sc);
                        if (sc->xl_type == XL_TYPE_905B) {
                                if (sc->xl_cdata.xl_tx_cnt) {
                                        int                     i;
                                        struct xl_chain         *c;

                                        i = sc->xl_cdata.xl_tx_cons;
                                        c = &sc->xl_cdata.xl_tx_chain[i];
                                        CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                                            c->xl_phys);
                                        CSR_WRITE_1(sc, XL_DOWN_POLL, 64);
                                        sc->xl_wdog_timer = 5;
                                }
                        } else {
                                if (sc->xl_cdata.xl_tx_head != NULL) {
                                        CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                                            sc->xl_cdata.xl_tx_head->xl_phys);
                                        sc->xl_wdog_timer = 5;
                                }
                        }
                        /*
                         * Remember to set this for the
                         * first generation 3c90X chips.
                         */
                        CSR_WRITE_1(sc, XL_TX_FREETHRESH, XL_PACKET_SIZE >> 8);
                        if (txstat & XL_TXSTATUS_UNDERRUN &&
                            sc->xl_tx_thresh < XL_PACKET_SIZE) {
                                sc->xl_tx_thresh += XL_MIN_FRAMELEN;
                                device_printf(sc->xl_dev,
"tx underrun, increasing tx start threshold to %d bytes\n", sc->xl_tx_thresh);
                        }
                        CSR_WRITE_2(sc, XL_COMMAND,
                            XL_CMD_TX_SET_START|sc->xl_tx_thresh);
                        if (sc->xl_type == XL_TYPE_905B) {
                                CSR_WRITE_2(sc, XL_COMMAND,
                                XL_CMD_SET_TX_RECLAIM|(XL_PACKET_SIZE >> 4));
                        }
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_ENABLE);
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                } else {
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_ENABLE);
                        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                }
                /*
                 * Write an arbitrary byte to the TX_STATUS register
                 * to clear this interrupt/error and advance to the next.
                 */
                CSR_WRITE_1(sc, XL_TX_STATUS, 0x01);
        }
}

static void
xl_intr(void *arg)
{
        struct xl_softc         *sc = arg;
        struct ifnet            *ifp = sc->xl_ifp;
        u_int16_t               status;

        XL_LOCK(sc);

#ifdef DEVICE_POLLING
        if (ifp->if_capenable & IFCAP_POLLING) {
                XL_UNLOCK(sc);
                return;
        }
#endif

        for (;;) {
                status = CSR_READ_2(sc, XL_STATUS);
                if ((status & XL_INTRS) == 0 || status == 0xFFFF)
                        break;
                CSR_WRITE_2(sc, XL_COMMAND,
                    XL_CMD_INTR_ACK|(status & XL_INTRS));
                if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
                        break;

                if (status & XL_STAT_UP_COMPLETE) {
                        if (xl_rxeof(sc) == 0) {
                                while (xl_rx_resync(sc))
                                        xl_rxeof(sc);
                        }
                }

                if (status & XL_STAT_DOWN_COMPLETE) {
                        if (sc->xl_type == XL_TYPE_905B)
                                xl_txeof_90xB(sc);
                        else
                                xl_txeof(sc);
                }

                if (status & XL_STAT_TX_COMPLETE) {
                        if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
                        xl_txeoc(sc);
                }

                if (status & XL_STAT_ADFAIL) {
                        ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
                        xl_init_locked(sc);
                        break;
                }

                if (status & XL_STAT_STATSOFLOW)
                        xl_stats_update(sc);
        }

        if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd) &&
            ifp->if_drv_flags & IFF_DRV_RUNNING) {
                if (sc->xl_type == XL_TYPE_905B)
                        xl_start_90xB_locked(ifp);
                else
                        xl_start_locked(ifp);
        }

        XL_UNLOCK(sc);
}

#ifdef DEVICE_POLLING
static int
xl_poll(struct ifnet *ifp, enum poll_cmd cmd, int count)
{
        struct xl_softc *sc = ifp->if_softc;
        int rx_npkts = 0;

        XL_LOCK(sc);
        if (ifp->if_drv_flags & IFF_DRV_RUNNING)
                rx_npkts = xl_poll_locked(ifp, cmd, count);
        XL_UNLOCK(sc);
        return (rx_npkts);
}

static int
xl_poll_locked(struct ifnet *ifp, enum poll_cmd cmd, int count)
{
        struct xl_softc *sc = ifp->if_softc;
        int rx_npkts;

        XL_LOCK_ASSERT(sc);

        sc->rxcycles = count;
        rx_npkts = xl_rxeof(sc);
        if (sc->xl_type == XL_TYPE_905B)
                xl_txeof_90xB(sc);
        else
                xl_txeof(sc);

        if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd)) {
                if (sc->xl_type == XL_TYPE_905B)
                        xl_start_90xB_locked(ifp);
                else
                        xl_start_locked(ifp);
        }

        if (cmd == POLL_AND_CHECK_STATUS) {
                u_int16_t status;

                status = CSR_READ_2(sc, XL_STATUS);
                if (status & XL_INTRS && status != 0xFFFF) {
                        CSR_WRITE_2(sc, XL_COMMAND,
                            XL_CMD_INTR_ACK|(status & XL_INTRS));

                        if (status & XL_STAT_TX_COMPLETE) {
                                if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
                                xl_txeoc(sc);
                        }

                        if (status & XL_STAT_ADFAIL) {
                                ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
                                xl_init_locked(sc);
                        }

                        if (status & XL_STAT_STATSOFLOW)
                                xl_stats_update(sc);
                }
        }
        return (rx_npkts);
}
#endif /* DEVICE_POLLING */

static void
xl_tick(void *xsc)
{
        struct xl_softc *sc = xsc;
        struct mii_data *mii;

        XL_LOCK_ASSERT(sc);

        if (sc->xl_miibus != NULL) {
                mii = device_get_softc(sc->xl_miibus);
                mii_tick(mii);
        }

        xl_stats_update(sc);
        if (xl_watchdog(sc) == EJUSTRETURN)
                return;

        callout_reset(&sc->xl_tick_callout, hz, xl_tick, sc);
}

static void
xl_stats_update(struct xl_softc *sc)
{
        struct ifnet            *ifp = sc->xl_ifp;
        struct xl_stats         xl_stats;
        u_int8_t                *p;
        int                     i;

        XL_LOCK_ASSERT(sc);

        bzero((char *)&xl_stats, sizeof(struct xl_stats));

        p = (u_int8_t *)&xl_stats;

        /* Read all the stats registers. */
        XL_SEL_WIN(6);

        for (i = 0; i < 16; i++)
                *p++ = CSR_READ_1(sc, XL_W6_CARRIER_LOST + i);

        if_inc_counter(ifp, IFCOUNTER_IERRORS, xl_stats.xl_rx_overrun);

        if_inc_counter(ifp, IFCOUNTER_COLLISIONS,
            xl_stats.xl_tx_multi_collision +
            xl_stats.xl_tx_single_collision +
            xl_stats.xl_tx_late_collision);

        /*
         * Boomerang and cyclone chips have an extra stats counter
         * in window 4 (BadSSD). We have to read this too in order
         * to clear out all the stats registers and avoid a statsoflow
         * interrupt.
         */
        XL_SEL_WIN(4);
        CSR_READ_1(sc, XL_W4_BADSSD);
        XL_SEL_WIN(7);
}

/*
 * Encapsulate an mbuf chain in a descriptor by coupling the mbuf data
 * pointers to the fragment pointers.
 */
static int
xl_encap(struct xl_softc *sc, struct xl_chain *c, struct mbuf **m_head)
{
        struct mbuf             *m_new;
        struct ifnet            *ifp = sc->xl_ifp;
        int                     error, i, nseg, total_len;
        u_int32_t               status;

        XL_LOCK_ASSERT(sc);

        error = bus_dmamap_load_mbuf_sg(sc->xl_mtag, c->xl_map, *m_head,
            sc->xl_cdata.xl_tx_segs, &nseg, BUS_DMA_NOWAIT);

        if (error && error != EFBIG) {
                if_printf(ifp, "can't map mbuf (error %d)\n", error);
                return (error);
        }

        /*
         * Handle special case: we used up all 63 fragments,
         * but we have more mbufs left in the chain. Copy the
         * data into an mbuf cluster. Note that we don't
         * bother clearing the values in the other fragment
         * pointers/counters; it wouldn't gain us anything,
         * and would waste cycles.
         */
        if (error) {
                m_new = m_collapse(*m_head, M_NOWAIT, XL_MAXFRAGS);
                if (m_new == NULL) {
                        m_freem(*m_head);
                        *m_head = NULL;
                        return (ENOBUFS);
                }
                *m_head = m_new;

                error = bus_dmamap_load_mbuf_sg(sc->xl_mtag, c->xl_map,
                    *m_head, sc->xl_cdata.xl_tx_segs, &nseg, BUS_DMA_NOWAIT);
                if (error) {
                        m_freem(*m_head);
                        *m_head = NULL;
                        if_printf(ifp, "can't map mbuf (error %d)\n", error);
                        return (error);
                }
        }

        KASSERT(nseg <= XL_MAXFRAGS,
            ("%s: too many DMA segments (%d)", __func__, nseg));
        if (nseg == 0) {
                m_freem(*m_head);
                *m_head = NULL;
                return (EIO);
        }
        bus_dmamap_sync(sc->xl_mtag, c->xl_map, BUS_DMASYNC_PREWRITE);

        total_len = 0;
        for (i = 0; i < nseg; i++) {
                KASSERT(sc->xl_cdata.xl_tx_segs[i].ds_len <= MCLBYTES,
                    ("segment size too large"));
                c->xl_ptr->xl_frag[i].xl_addr =
                    htole32(sc->xl_cdata.xl_tx_segs[i].ds_addr);
                c->xl_ptr->xl_frag[i].xl_len =
                    htole32(sc->xl_cdata.xl_tx_segs[i].ds_len);
                total_len += sc->xl_cdata.xl_tx_segs[i].ds_len;
        }
        c->xl_ptr->xl_frag[nseg - 1].xl_len |= htole32(XL_LAST_FRAG);

        if (sc->xl_type == XL_TYPE_905B) {
                status = XL_TXSTAT_RND_DEFEAT;

#ifndef XL905B_TXCSUM_BROKEN
                if ((*m_head)->m_pkthdr.csum_flags) {
                        if ((*m_head)->m_pkthdr.csum_flags & CSUM_IP)
                                status |= XL_TXSTAT_IPCKSUM;
                        if ((*m_head)->m_pkthdr.csum_flags & CSUM_TCP)
                                status |= XL_TXSTAT_TCPCKSUM;
                        if ((*m_head)->m_pkthdr.csum_flags & CSUM_UDP)
                                status |= XL_TXSTAT_UDPCKSUM;
                }
#endif
        } else
                status = total_len;
        c->xl_ptr->xl_status = htole32(status);
        c->xl_ptr->xl_next = 0;

        c->xl_mbuf = *m_head;
        return (0);
}

/*
 * Main transmit routine. To avoid having to do mbuf copies, we put pointers
 * to the mbuf data regions directly in the transmit lists. We also save a
 * copy of the pointers since the transmit list fragment pointers are
 * physical addresses.
 */

static void
xl_start(struct ifnet *ifp)
{
        struct xl_softc         *sc = ifp->if_softc;

        XL_LOCK(sc);

        if (sc->xl_type == XL_TYPE_905B)
                xl_start_90xB_locked(ifp);
        else
                xl_start_locked(ifp);

        XL_UNLOCK(sc);
}

static void
xl_start_locked(struct ifnet *ifp)
{
        struct xl_softc         *sc = ifp->if_softc;
        struct mbuf             *m_head;
        struct xl_chain         *prev = NULL, *cur_tx = NULL, *start_tx;
        struct xl_chain         *prev_tx;
        int                     error;

        XL_LOCK_ASSERT(sc);

        if ((ifp->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
            IFF_DRV_RUNNING)
                return;
        /*
         * Check for an available queue slot. If there are none,
         * punt.
         */
        if (sc->xl_cdata.xl_tx_free == NULL) {
                xl_txeoc(sc);
                xl_txeof(sc);
                if (sc->xl_cdata.xl_tx_free == NULL) {
                        ifp->if_drv_flags |= IFF_DRV_OACTIVE;
                        return;
                }
        }

        start_tx = sc->xl_cdata.xl_tx_free;

        for (; !IFQ_DRV_IS_EMPTY(&ifp->if_snd) &&
            sc->xl_cdata.xl_tx_free != NULL;) {
                IFQ_DRV_DEQUEUE(&ifp->if_snd, m_head);
                if (m_head == NULL)
                        break;

                /* Pick a descriptor off the free list. */
                prev_tx = cur_tx;
                cur_tx = sc->xl_cdata.xl_tx_free;

                /* Pack the data into the descriptor. */
                error = xl_encap(sc, cur_tx, &m_head);
                if (error) {
                        cur_tx = prev_tx;
                        if (m_head == NULL)
                                break;
                        ifp->if_drv_flags |= IFF_DRV_OACTIVE;
                        IFQ_DRV_PREPEND(&ifp->if_snd, m_head);
                        break;
                }

                sc->xl_cdata.xl_tx_free = cur_tx->xl_next;
                cur_tx->xl_next = NULL;

                /* Chain it together. */
                if (prev != NULL) {
                        prev->xl_next = cur_tx;
                        prev->xl_ptr->xl_next = htole32(cur_tx->xl_phys);
                }
                prev = cur_tx;

                /*
                 * If there's a BPF listener, bounce a copy of this frame
                 * to him.
                 */
                BPF_MTAP(ifp, cur_tx->xl_mbuf);
        }

        /*
         * If there are no packets queued, bail.
         */
        if (cur_tx == NULL)
                return;

        /*
         * Place the request for the upload interrupt
         * in the last descriptor in the chain. This way, if
         * we're chaining several packets at once, we'll only
         * get an interrupt once for the whole chain rather than
         * once for each packet.
         */
        cur_tx->xl_ptr->xl_status |= htole32(XL_TXSTAT_DL_INTR);

        /*
         * Queue the packets. If the TX channel is clear, update
         * the downlist pointer register.
         */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_STALL);
        xl_wait(sc);

        if (sc->xl_cdata.xl_tx_head != NULL) {
                sc->xl_cdata.xl_tx_tail->xl_next = start_tx;
                sc->xl_cdata.xl_tx_tail->xl_ptr->xl_next =
                    htole32(start_tx->xl_phys);
                sc->xl_cdata.xl_tx_tail->xl_ptr->xl_status &=
                    htole32(~XL_TXSTAT_DL_INTR);
                sc->xl_cdata.xl_tx_tail = cur_tx;
        } else {
                sc->xl_cdata.xl_tx_head = start_tx;
                sc->xl_cdata.xl_tx_tail = cur_tx;
        }
        bus_dmamap_sync(sc->xl_ldata.xl_tx_tag, sc->xl_ldata.xl_tx_dmamap,
            BUS_DMASYNC_PREWRITE);
        if (!CSR_READ_4(sc, XL_DOWNLIST_PTR))
                CSR_WRITE_4(sc, XL_DOWNLIST_PTR, start_tx->xl_phys);

        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);

        XL_SEL_WIN(7);

        /*
         * Set a timeout in case the chip goes out to lunch.
         */
        sc->xl_wdog_timer = 5;

        /*
         * XXX Under certain conditions, usually on slower machines
         * where interrupts may be dropped, it's possible for the
         * adapter to chew up all the buffers in the receive ring
         * and stall, without us being able to do anything about it.
         * To guard against this, we need to make a pass over the
         * RX queue to make sure there aren't any packets pending.
         * Doing it here means we can flush the receive ring at the
         * same time the chip is DMAing the transmit descriptors we
         * just gave it.
         *
         * 3Com goes to some lengths to emphasize the Parallel Tasking (tm)
         * nature of their chips in all their marketing literature;
         * we may as well take advantage of it. :)
         */
        taskqueue_enqueue(taskqueue_swi, &sc->xl_task);
}

static void
xl_start_90xB_locked(struct ifnet *ifp)
{
        struct xl_softc         *sc = ifp->if_softc;
        struct mbuf             *m_head;
        struct xl_chain         *prev = NULL, *cur_tx = NULL, *start_tx;
        struct xl_chain         *prev_tx;
        int                     error, idx;

        XL_LOCK_ASSERT(sc);

        if ((ifp->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
            IFF_DRV_RUNNING)
                return;

        idx = sc->xl_cdata.xl_tx_prod;
        start_tx = &sc->xl_cdata.xl_tx_chain[idx];

        for (; !IFQ_DRV_IS_EMPTY(&ifp->if_snd) &&
            sc->xl_cdata.xl_tx_chain[idx].xl_mbuf == NULL;) {
                if ((XL_TX_LIST_CNT - sc->xl_cdata.xl_tx_cnt) < 3) {
                        ifp->if_drv_flags |= IFF_DRV_OACTIVE;
                        break;
                }

                IFQ_DRV_DEQUEUE(&ifp->if_snd, m_head);
                if (m_head == NULL)
                        break;

                prev_tx = cur_tx;
                cur_tx = &sc->xl_cdata.xl_tx_chain[idx];

                /* Pack the data into the descriptor. */
                error = xl_encap(sc, cur_tx, &m_head);
                if (error) {
                        cur_tx = prev_tx;
                        if (m_head == NULL)
                                break;
                        ifp->if_drv_flags |= IFF_DRV_OACTIVE;
                        IFQ_DRV_PREPEND(&ifp->if_snd, m_head);
                        break;
                }

                /* Chain it together. */
                if (prev != NULL)
                        prev->xl_ptr->xl_next = htole32(cur_tx->xl_phys);
                prev = cur_tx;

                /*
                 * If there's a BPF listener, bounce a copy of this frame
                 * to him.
                 */
                BPF_MTAP(ifp, cur_tx->xl_mbuf);

                XL_INC(idx, XL_TX_LIST_CNT);
                sc->xl_cdata.xl_tx_cnt++;
        }

        /*
         * If there are no packets queued, bail.
         */
        if (cur_tx == NULL)
                return;

        /*
         * Place the request for the upload interrupt
         * in the last descriptor in the chain. This way, if
         * we're chaining several packets at once, we'll only
         * get an interrupt once for the whole chain rather than
         * once for each packet.
         */
        cur_tx->xl_ptr->xl_status |= htole32(XL_TXSTAT_DL_INTR);

        /* Start transmission */
        sc->xl_cdata.xl_tx_prod = idx;
        start_tx->xl_prev->xl_ptr->xl_next = htole32(start_tx->xl_phys);
        bus_dmamap_sync(sc->xl_ldata.xl_tx_tag, sc->xl_ldata.xl_tx_dmamap,
            BUS_DMASYNC_PREWRITE);

        /*
         * Set a timeout in case the chip goes out to lunch.
         */
        sc->xl_wdog_timer = 5;
}

static void
xl_init(void *xsc)
{
        struct xl_softc         *sc = xsc;

        XL_LOCK(sc);
        xl_init_locked(sc);
        XL_UNLOCK(sc);
}

static void
xl_init_locked(struct xl_softc *sc)
{
        struct ifnet            *ifp = sc->xl_ifp;
        int                     error, i;
        struct mii_data         *mii = NULL;

        XL_LOCK_ASSERT(sc);

        if ((ifp->if_drv_flags & IFF_DRV_RUNNING) != 0)
                return;
        /*
         * Cancel pending I/O and free all RX/TX buffers.
         */
        xl_stop(sc);

        /* Reset the chip to a known state. */
        xl_reset(sc);

        if (sc->xl_miibus == NULL) {
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
                xl_wait(sc);
        }
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
        xl_wait(sc);
        DELAY(10000);

        if (sc->xl_miibus != NULL)
                mii = device_get_softc(sc->xl_miibus);

        /*
         * Clear WOL status and disable all WOL feature as WOL
         * would interfere Rx operation under normal environments.
         */
        if ((sc->xl_flags & XL_FLAG_WOL) != 0) {
                XL_SEL_WIN(7);
                CSR_READ_2(sc, XL_W7_BM_PME);
                CSR_WRITE_2(sc, XL_W7_BM_PME, 0);
        }
        /* Init our MAC address */
        XL_SEL_WIN(2);
        for (i = 0; i < ETHER_ADDR_LEN; i++) {
                CSR_WRITE_1(sc, XL_W2_STATION_ADDR_LO + i,
                                IF_LLADDR(sc->xl_ifp)[i]);
        }

        /* Clear the station mask. */
        for (i = 0; i < 3; i++)
                CSR_WRITE_2(sc, XL_W2_STATION_MASK_LO + (i * 2), 0);
#ifdef notdef
        /* Reset TX and RX. */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
        xl_wait(sc);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
        xl_wait(sc);
#endif
        /* Init circular RX list. */
        error = xl_list_rx_init(sc);
        if (error) {
                device_printf(sc->xl_dev, "initialization of the rx ring failed (%d)\n",
                    error);
                xl_stop(sc);
                return;
        }

        /* Init TX descriptors. */
        if (sc->xl_type == XL_TYPE_905B)
                error = xl_list_tx_init_90xB(sc);
        else
                error = xl_list_tx_init(sc);
        if (error) {
                device_printf(sc->xl_dev, "initialization of the tx ring failed (%d)\n",
                    error);
                xl_stop(sc);
                return;
        }

        /*
         * Set the TX freethresh value.
         * Note that this has no effect on 3c905B "cyclone"
         * cards but is required for 3c900/3c905 "boomerang"
         * cards in order to enable the download engine.
         */
        CSR_WRITE_1(sc, XL_TX_FREETHRESH, XL_PACKET_SIZE >> 8);

        /* Set the TX start threshold for best performance. */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_SET_START|sc->xl_tx_thresh);

        /*
         * If this is a 3c905B, also set the tx reclaim threshold.
         * This helps cut down on the number of tx reclaim errors
         * that could happen on a busy network. The chip multiplies
         * the register value by 16 to obtain the actual threshold
         * in bytes, so we divide by 16 when setting the value here.
         * The existing threshold value can be examined by reading
         * the register at offset 9 in window 5.
         */
        if (sc->xl_type == XL_TYPE_905B) {
                CSR_WRITE_2(sc, XL_COMMAND,
                    XL_CMD_SET_TX_RECLAIM|(XL_PACKET_SIZE >> 4));
        }

        /* Set RX filter bits. */
        xl_rxfilter(sc);

        /*
         * Load the address of the RX list. We have to
         * stall the upload engine before we can manipulate
         * the uplist pointer register, then unstall it when
         * we're finished. We also have to wait for the
         * stall command to complete before proceeding.
         * Note that we have to do this after any RX resets
         * have completed since the uplist register is cleared
         * by a reset.
         */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_STALL);
        xl_wait(sc);
        CSR_WRITE_4(sc, XL_UPLIST_PTR, sc->xl_ldata.xl_rx_dmaaddr);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_UP_UNSTALL);
        xl_wait(sc);

        if (sc->xl_type == XL_TYPE_905B) {
                /* Set polling interval */
                CSR_WRITE_1(sc, XL_DOWN_POLL, 64);
                /* Load the address of the TX list */
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_STALL);
                xl_wait(sc);
                CSR_WRITE_4(sc, XL_DOWNLIST_PTR,
                    sc->xl_cdata.xl_tx_chain[0].xl_phys);
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_DOWN_UNSTALL);
                xl_wait(sc);
        }

        /*
         * If the coax transceiver is on, make sure to enable
         * the DC-DC converter.
         */
        XL_SEL_WIN(3);
        if (sc->xl_xcvr == XL_XCVR_COAX)
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_START);
        else
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);

        /*
         * increase packet size to allow reception of 802.1q or ISL packets.
         * For the 3c90x chip, set the 'allow large packets' bit in the MAC
         * control register. For 3c90xB/C chips, use the RX packet size
         * register.
         */

        if (sc->xl_type == XL_TYPE_905B)
                CSR_WRITE_2(sc, XL_W3_MAXPKTSIZE, XL_PACKET_SIZE);
        else {
                u_int8_t macctl;
                macctl = CSR_READ_1(sc, XL_W3_MAC_CTRL);
                macctl |= XL_MACCTRL_ALLOW_LARGE_PACK;
                CSR_WRITE_1(sc, XL_W3_MAC_CTRL, macctl);
        }

        /* Clear out the stats counters. */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STATS_DISABLE);
        xl_stats_update(sc);
        XL_SEL_WIN(4);
        CSR_WRITE_2(sc, XL_W4_NET_DIAG, XL_NETDIAG_UPPER_BYTES_ENABLE);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STATS_ENABLE);

        /*
         * Enable interrupts.
         */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ACK|0xFF);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STAT_ENB|XL_INTRS);
#ifdef DEVICE_POLLING
        /* Disable interrupts if we are polling. */
        if (ifp->if_capenable & IFCAP_POLLING)
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ENB|0);
        else
#endif
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ENB|XL_INTRS);
        if (sc->xl_flags & XL_FLAG_FUNCREG)
            bus_space_write_4(sc->xl_ftag, sc->xl_fhandle, 4, 0x8000);

        /* Set the RX early threshold */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_SET_THRESH|(XL_PACKET_SIZE >>2));
        CSR_WRITE_4(sc, XL_DMACTL, XL_DMACTL_UP_RX_EARLY);

        /* Enable receiver and transmitter. */
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_ENABLE);
        xl_wait(sc);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_ENABLE);
        xl_wait(sc);

        /* XXX Downcall to miibus. */
        if (mii != NULL)
                mii_mediachg(mii);

        /* Select window 7 for normal operations. */
        XL_SEL_WIN(7);

        ifp->if_drv_flags |= IFF_DRV_RUNNING;
        ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;

        sc->xl_wdog_timer = 0;
        callout_reset(&sc->xl_tick_callout, hz, xl_tick, sc);
}

/*
 * Set media options.
 */
static int
xl_ifmedia_upd(struct ifnet *ifp)
{
        struct xl_softc         *sc = ifp->if_softc;
        struct ifmedia          *ifm = NULL;
        struct mii_data         *mii = NULL;

        XL_LOCK(sc);

        if (sc->xl_miibus != NULL)
                mii = device_get_softc(sc->xl_miibus);
        if (mii == NULL)
                ifm = &sc->ifmedia;
        else
                ifm = &mii->mii_media;

        switch (IFM_SUBTYPE(ifm->ifm_media)) {
        case IFM_100_FX:
        case IFM_10_FL:
        case IFM_10_2:
        case IFM_10_5:
                xl_setmode(sc, ifm->ifm_media);
                XL_UNLOCK(sc);
                return (0);
        }

        if (sc->xl_media & XL_MEDIAOPT_MII ||
            sc->xl_media & XL_MEDIAOPT_BTX ||
            sc->xl_media & XL_MEDIAOPT_BT4) {
                ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
                xl_init_locked(sc);
        } else {
                xl_setmode(sc, ifm->ifm_media);
        }

        XL_UNLOCK(sc);

        return (0);
}

/*
 * Report current media status.
 */
static void
xl_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
{
        struct xl_softc         *sc = ifp->if_softc;
        u_int32_t               icfg;
        u_int16_t               status = 0;
        struct mii_data         *mii = NULL;

        XL_LOCK(sc);

        if (sc->xl_miibus != NULL)
                mii = device_get_softc(sc->xl_miibus);

        XL_SEL_WIN(4);
        status = CSR_READ_2(sc, XL_W4_MEDIA_STATUS);

        XL_SEL_WIN(3);
        icfg = CSR_READ_4(sc, XL_W3_INTERNAL_CFG) & XL_ICFG_CONNECTOR_MASK;
        icfg >>= XL_ICFG_CONNECTOR_BITS;

        ifmr->ifm_active = IFM_ETHER;
        ifmr->ifm_status = IFM_AVALID;

        if ((status & XL_MEDIASTAT_CARRIER) == 0)
                ifmr->ifm_status |= IFM_ACTIVE;

        switch (icfg) {
        case XL_XCVR_10BT:
                ifmr->ifm_active = IFM_ETHER|IFM_10_T;
                if (CSR_READ_1(sc, XL_W3_MAC_CTRL) & XL_MACCTRL_DUPLEX)
                        ifmr->ifm_active |= IFM_FDX;
                else
                        ifmr->ifm_active |= IFM_HDX;
                break;
        case XL_XCVR_AUI:
                if (sc->xl_type == XL_TYPE_905B &&
                    sc->xl_media == XL_MEDIAOPT_10FL) {
                        ifmr->ifm_active = IFM_ETHER|IFM_10_FL;
                        if (CSR_READ_1(sc, XL_W3_MAC_CTRL) & XL_MACCTRL_DUPLEX)
                                ifmr->ifm_active |= IFM_FDX;
                        else
                                ifmr->ifm_active |= IFM_HDX;
                } else
                        ifmr->ifm_active = IFM_ETHER|IFM_10_5;
                break;
        case XL_XCVR_COAX:
                ifmr->ifm_active = IFM_ETHER|IFM_10_2;
                break;
        /*
         * XXX MII and BTX/AUTO should be separate cases.
         */

        case XL_XCVR_100BTX:
        case XL_XCVR_AUTO:
        case XL_XCVR_MII:
                if (mii != NULL) {
                        mii_pollstat(mii);
                        ifmr->ifm_active = mii->mii_media_active;
                        ifmr->ifm_status = mii->mii_media_status;
                }
                break;
        case XL_XCVR_100BFX:
                ifmr->ifm_active = IFM_ETHER|IFM_100_FX;
                break;
        default:
                if_printf(ifp, "unknown XCVR type: %d\n", icfg);
                break;
        }

        XL_UNLOCK(sc);
}

static int
xl_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
{
        struct xl_softc         *sc = ifp->if_softc;
        struct ifreq            *ifr = (struct ifreq *) data;
        int                     error = 0, mask;
        struct mii_data         *mii = NULL;

        switch (command) {
        case SIOCSIFFLAGS:
                XL_LOCK(sc);
                if (ifp->if_flags & IFF_UP) {
                        if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
                            (ifp->if_flags ^ sc->xl_if_flags) &
                            (IFF_PROMISC | IFF_ALLMULTI))
                                xl_rxfilter(sc);
                        else
                                xl_init_locked(sc);
                } else {
                        if (ifp->if_drv_flags & IFF_DRV_RUNNING)
                                xl_stop(sc);
                }
                sc->xl_if_flags = ifp->if_flags;
                XL_UNLOCK(sc);
                break;
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                /* XXX Downcall from if_addmulti() possibly with locks held. */
                XL_LOCK(sc);
                if (ifp->if_drv_flags & IFF_DRV_RUNNING)
                        xl_rxfilter(sc);
                XL_UNLOCK(sc);
                break;
        case SIOCGIFMEDIA:
        case SIOCSIFMEDIA:
                if (sc->xl_miibus != NULL)
                        mii = device_get_softc(sc->xl_miibus);
                if (mii == NULL)
                        error = ifmedia_ioctl(ifp, ifr,
                            &sc->ifmedia, command);
                else
                        error = ifmedia_ioctl(ifp, ifr,
                            &mii->mii_media, command);
                break;
        case SIOCSIFCAP:
                mask = ifr->ifr_reqcap ^ ifp->if_capenable;
#ifdef DEVICE_POLLING
                if ((mask & IFCAP_POLLING) != 0 &&
                    (ifp->if_capabilities & IFCAP_POLLING) != 0) {
                        ifp->if_capenable ^= IFCAP_POLLING;
                        if ((ifp->if_capenable & IFCAP_POLLING) != 0) {
                                error = ether_poll_register(xl_poll, ifp);
                                if (error)
                                        break;
                                XL_LOCK(sc);
                                /* Disable interrupts */
                                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ENB|0);
                                ifp->if_capenable |= IFCAP_POLLING;
                                XL_UNLOCK(sc);
                        } else {
                                error = ether_poll_deregister(ifp);
                                /* Enable interrupts. */
                                XL_LOCK(sc);
                                CSR_WRITE_2(sc, XL_COMMAND,
                                    XL_CMD_INTR_ACK | 0xFF);
                                CSR_WRITE_2(sc, XL_COMMAND,
                                    XL_CMD_INTR_ENB | XL_INTRS);
                                if (sc->xl_flags & XL_FLAG_FUNCREG)
                                        bus_space_write_4(sc->xl_ftag,
                                            sc->xl_fhandle, 4, 0x8000);
                                XL_UNLOCK(sc);
                        }
                }
#endif /* DEVICE_POLLING */
                XL_LOCK(sc);
                if ((mask & IFCAP_TXCSUM) != 0 &&
                    (ifp->if_capabilities & IFCAP_TXCSUM) != 0) {
                        ifp->if_capenable ^= IFCAP_TXCSUM;
                        if ((ifp->if_capenable & IFCAP_TXCSUM) != 0)
                                ifp->if_hwassist |= XL905B_CSUM_FEATURES;
                        else
                                ifp->if_hwassist &= ~XL905B_CSUM_FEATURES;
                }
                if ((mask & IFCAP_RXCSUM) != 0 &&
                    (ifp->if_capabilities & IFCAP_RXCSUM) != 0)
                        ifp->if_capenable ^= IFCAP_RXCSUM;
                if ((mask & IFCAP_WOL_MAGIC) != 0 &&
                    (ifp->if_capabilities & IFCAP_WOL_MAGIC) != 0)
                        ifp->if_capenable ^= IFCAP_WOL_MAGIC;
                XL_UNLOCK(sc);
                break;
        default:
                error = ether_ioctl(ifp, command, data);
                break;
        }

        return (error);
}

static int
xl_watchdog(struct xl_softc *sc)
{
        struct ifnet            *ifp = sc->xl_ifp;
        u_int16_t               status = 0;
        int                     misintr;

        XL_LOCK_ASSERT(sc);

        if (sc->xl_wdog_timer == 0 || --sc->xl_wdog_timer != 0)
                return (0);

        xl_rxeof(sc);
        xl_txeoc(sc);
        misintr = 0;
        if (sc->xl_type == XL_TYPE_905B) {
                xl_txeof_90xB(sc);
                if (sc->xl_cdata.xl_tx_cnt == 0)
                        misintr++;
        } else {
                xl_txeof(sc);
                if (sc->xl_cdata.xl_tx_head == NULL)
                        misintr++;
        }
        if (misintr != 0) {
                device_printf(sc->xl_dev,
                    "watchdog timeout (missed Tx interrupts) -- recovering\n");
                return (0);
        }

        if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
        XL_SEL_WIN(4);
        status = CSR_READ_2(sc, XL_W4_MEDIA_STATUS);
        device_printf(sc->xl_dev, "watchdog timeout\n");

        if (status & XL_MEDIASTAT_CARRIER)
                device_printf(sc->xl_dev,
                    "no carrier - transceiver cable problem?\n");

        ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
        xl_init_locked(sc);

        if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd)) {
                if (sc->xl_type == XL_TYPE_905B)
                        xl_start_90xB_locked(ifp);
                else
                        xl_start_locked(ifp);
        }

        return (EJUSTRETURN);
}

/*
 * Stop the adapter and free any mbufs allocated to the
 * RX and TX lists.
 */
static void
xl_stop(struct xl_softc *sc)
{
        register int            i;
        struct ifnet            *ifp = sc->xl_ifp;

        XL_LOCK_ASSERT(sc);

        sc->xl_wdog_timer = 0;

        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_DISABLE);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STATS_DISABLE);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ENB);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_DISCARD);
        xl_wait(sc);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_DISABLE);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_COAX_STOP);
        DELAY(800);

#ifdef foo
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_RESET);
        xl_wait(sc);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_TX_RESET);
        xl_wait(sc);
#endif

        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ACK|XL_STAT_INTLATCH);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_STAT_ENB|0);
        CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_INTR_ENB|0);
        if (sc->xl_flags & XL_FLAG_FUNCREG)
                bus_space_write_4(sc->xl_ftag, sc->xl_fhandle, 4, 0x8000);

        /* Stop the stats updater. */
        callout_stop(&sc->xl_tick_callout);

        /*
         * Free data in the RX lists.
         */
        for (i = 0; i < XL_RX_LIST_CNT; i++) {
                if (sc->xl_cdata.xl_rx_chain[i].xl_mbuf != NULL) {
                        bus_dmamap_unload(sc->xl_mtag,
                            sc->xl_cdata.xl_rx_chain[i].xl_map);
                        bus_dmamap_destroy(sc->xl_mtag,
                            sc->xl_cdata.xl_rx_chain[i].xl_map);
                        m_freem(sc->xl_cdata.xl_rx_chain[i].xl_mbuf);
                        sc->xl_cdata.xl_rx_chain[i].xl_mbuf = NULL;
                }
        }
        if (sc->xl_ldata.xl_rx_list != NULL)
                bzero(sc->xl_ldata.xl_rx_list, XL_RX_LIST_SZ);
        /*
         * Free the TX list buffers.
         */
        for (i = 0; i < XL_TX_LIST_CNT; i++) {
                if (sc->xl_cdata.xl_tx_chain[i].xl_mbuf != NULL) {
                        bus_dmamap_unload(sc->xl_mtag,
                            sc->xl_cdata.xl_tx_chain[i].xl_map);
                        bus_dmamap_destroy(sc->xl_mtag,
                            sc->xl_cdata.xl_tx_chain[i].xl_map);
                        m_freem(sc->xl_cdata.xl_tx_chain[i].xl_mbuf);
                        sc->xl_cdata.xl_tx_chain[i].xl_mbuf = NULL;
                }
        }
        if (sc->xl_ldata.xl_tx_list != NULL)
                bzero(sc->xl_ldata.xl_tx_list, XL_TX_LIST_SZ);

        ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
}

/*
 * Stop all chip I/O so that the kernel's probe routines don't
 * get confused by errant DMAs when rebooting.
 */
static int
xl_shutdown(device_t dev)
{

        return (xl_suspend(dev));
}

static int
xl_suspend(device_t dev)
{
        struct xl_softc         *sc;

        sc = device_get_softc(dev);

        XL_LOCK(sc);
        xl_stop(sc);
        xl_setwol(sc);
        XL_UNLOCK(sc);

        return (0);
}

static int
xl_resume(device_t dev)
{
        struct xl_softc         *sc;
        struct ifnet            *ifp;

        sc = device_get_softc(dev);
        ifp = sc->xl_ifp;

        XL_LOCK(sc);

        if (ifp->if_flags & IFF_UP) {
                ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
                xl_init_locked(sc);
        }

        XL_UNLOCK(sc);

        return (0);
}

static void
xl_setwol(struct xl_softc *sc)
{
        struct ifnet            *ifp;
        u_int16_t               cfg, pmstat;

        if ((sc->xl_flags & XL_FLAG_WOL) == 0)
                return;

        ifp = sc->xl_ifp;
        XL_SEL_WIN(7);
        /* Clear any pending PME events. */
        CSR_READ_2(sc, XL_W7_BM_PME);
        cfg = 0;
        if ((ifp->if_capenable & IFCAP_WOL_MAGIC) != 0)
                cfg |= XL_BM_PME_MAGIC;
        CSR_WRITE_2(sc, XL_W7_BM_PME, cfg);
        /* Enable RX. */
        if ((ifp->if_capenable & IFCAP_WOL_MAGIC) != 0)
                CSR_WRITE_2(sc, XL_COMMAND, XL_CMD_RX_ENABLE);
        /* Request PME. */
        pmstat = pci_read_config(sc->xl_dev,
            sc->xl_pmcap + PCIR_POWER_STATUS, 2);
        if ((ifp->if_capenable & IFCAP_WOL_MAGIC) != 0)
                pmstat |= PCIM_PSTAT_PMEENABLE;
        else
                pmstat &= ~PCIM_PSTAT_PMEENABLE;
        pci_write_config(sc->xl_dev,
            sc->xl_pmcap + PCIR_POWER_STATUS, pmstat, 2);
}