From 8520e7cbc1c74887ef634e1af7c57fdc54c4f159 Mon Sep 17 00:00:00 2001
From: Poul-Henning Kamp <phk@FreeBSD.org>
Date: Thu, 3 Apr 1997 09:43:50 +0000
Subject: [PATCH] If flag 0x4000 (Sleephack) is defined, assume that the disk
 is sleeping if all registers are 0xff.

This allows me to run with flags 0xc0ff on my IBM-DMCA-21440 disk, which
gives 5MB/sec sequential read :-)

If you have a laptop, try adding flag 0x4000 to your disk, and tell me if
it makes any difference for you.
---
 sys/i386/isa/wd.c | 38 +++++++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)

diff --git a/sys/i386/isa/wd.c b/sys/i386/isa/wd.c
index 3ce9fb5ea9b..401a35f8c7c 100644
--- a/sys/i386/isa/wd.c
+++ b/sys/i386/isa/wd.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)wd.c	7.2 (Berkeley) 5/9/91
- *	$Id: wd.c,v 1.126 1997/03/11 23:17:04 se Exp $
+ *	$Id: wd.c,v 1.127 1997/03/24 11:24:12 bde Exp $
  */
 
 /* TODO:
@@ -1392,9 +1392,41 @@ wdcommand(struct disk *du, u_int cylinder, u_int head, u_int sector,
 	u_int	wdc;
 
 	wdc = du->dk_port;
-	if (du->cfg_flags & WDOPT_SLEEPHACK)
-		if(inb(wdc + wd_status) == WDCS_BUSY)
+	if (du->cfg_flags & WDOPT_SLEEPHACK) {
+		/* OK, so the APM bios has put the disk into SLEEP mode,
+		 * how can we tell ?  Uhm, we can't.  There is no 
+		 * standardized way of finding out, and the only way to
+		 * wake it up is to reset it.  Bummer.
+		 *
+		 * All the many and varied versions of the IDE/ATA standard
+		 * explicitly tells us not to look at these registers if
+		 * the disk is in SLEEP mode.  Well, too bad really, we
+		 * have to find out if it's in sleep mode before we can 
+		 * avoid reading the registers.
+		 *
+		 * I have reason to belive that most disks will return
+		 * either 0xff or 0x00 in all but the status register 
+		 * when in SLEEP mode, but I have yet to see one return 
+		 * 0x00, so we don't check for that yet.
+		 *
+		 * The check for WDCS_BUSY is for the case where the
+		 * bios spins up the disk for us, but doesn't initialize
+		 * it correctly					/phk
+		 */
+		if(inb(wdc + wd_precomp) + inb(wdc + wd_cyl_lo) +
+		    inb(wdc + wd_cyl_hi) + inb(wdc + wd_sdh) +
+		    inb(wdc + wd_sector) + inb(wdc + wd_seccnt) == 6 * 0xff) {
+			if (bootverbose)
+				printf("wd(%d,%d): disk aSLEEP\n",
+					du->dk_ctrlr, du->dk_unit);
 			wdunwedge(du);
+		} else if(inb(wdc + wd_status) == WDCS_BUSY) {
+			if (bootverbose)
+				printf("wd(%d,%d): disk is BUSY\n",
+					du->dk_ctrlr, du->dk_unit);
+			wdunwedge(du);
+		}
+	}
 
 	if (wdwait(du, 0, TIMEOUT) < 0)
 		return (1);
-- 
2.45.2