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32 .Nd Serial ATA Advanced Host Controller Interface driver
34 To compile this driver into the kernel,
35 place the following lines in your
36 kernel configuration file:
37 .Bd -ragged -offset indent
43 Alternatively, to load the driver as a
44 module at boot time, place the following line in
46 .Bd -literal -offset indent
50 The following tunables are settable from the
53 .It Va hint.ahci. Ns Ar X Ns Va .msi
54 controls Message Signaled Interrupts (MSI) usage by the specified controller.
56 .Bl -tag -width 4n -offset indent -compact
60 single MSI vector used, if supported;
62 multiple MSI vectors used, if supported (default);
64 .It Va hint.ahci. Ns Ar X Ns Va .ccc
65 controls Command Completion Coalescing (CCC) usage by the specified controller.
66 Non-zero value enables CCC and defines maximum time (in ms), request can wait
67 for interrupt, if there are some more requests present on controller queue.
68 CCC reduces number of context switches on systems with many parallel requests,
69 but it can decrease disk performance on some workloads due to additional
71 .It Va hint.ahci. Ns Ar X Ns Va .direct
72 controls whether the driver should use direct command completion from
73 interrupt thread(s), or queue them to CAM completion threads.
74 Default value depends on number of MSI interrupts supported and number of
75 implemented SATA ports.
76 .It Va hint.ahci. Ns Ar X Ns Va .em
77 controls whether the driver should implement virtual enclosure management
78 device on top of SGPIO or other interface.
79 Default value depends on controller capabilities.
80 .It Va hint.ahcich. Ns Ar X Ns Va .pm_level
81 controls SATA interface Power Management for the specified channel,
82 allowing some power to be saved at the cost of additional command
86 .Bl -tag -width 4n -offset indent -compact
88 interface Power Management is disabled (default);
90 device is allowed to initiate PM state change, host is passive;
92 host initiates PARTIAL PM state transition every time port becomes idle;
94 host initiates SLUMBER PM state transition every time port becomes idle.
96 driver initiates PARTIAL PM state transition 1ms after port becomes idle;
98 driver initiates SLUMBER PM state transition 125ms after port becomes idle.
101 Some controllers, such as ICH8, do not implement modes 2 and 3 with NCQ used.
102 Because of artificial entering latency, performance degradation in modes
103 4 and 5 is much smaller then in modes 2 and 3.
105 Note that interface Power Management complicates device presence detection.
106 A manual bus reset/rescan may be needed after device hot-plug, unless hardware
107 implements Cold Presence Detection.
108 .It Va hint.ahcich. Ns Ar X Ns Va .sata_rev
109 setting to nonzero value limits maximum SATA revision (speed).
110 Values 1, 2 and 3 are respectively 1.5, 3 and 6Gbps.
112 setting to nonzero value forces driver attach to some known AHCI-capable
113 chips even if they are configured for legacy IDE emulation.
117 This driver provides the
119 subsystem with native access to the
121 ports of AHCI-compatible controllers.
122 Each SATA port found is represented to CAM as a separate bus with one
123 target, or, if HBA supports Port Multipliers, 16 targets.
124 Most of the bus-management details are handled by the SATA-specific
126 Connected ATA disks are handled by the ATA protocol disk peripheral driver
128 ATAPI devices are handled by the SCSI protocol peripheral drivers
134 Driver features include support for Serial ATA and ATAPI devices,
135 Port Multipliers (including FIS-based switching, when supported),
136 hardware command queues (up to 32 commands per port),
137 Native Command Queuing, SATA interface Power Management, device hot-plug
138 and Message Signaled Interrupts.
140 Driver supports "LED" enclosure management messages, defined by the AHCI.
141 When supported by hardware, it allows to control per-port activity, locate
142 and fault LEDs via the
146 device for localization and status reporting purposes.
147 Supporting AHCI controllers may transmit that information to the backplane
148 controllers via SGPIO interface.
149 Backplane controllers interpret received
150 statuses in some way (IBPI standard) to report them using present indicators.
154 driver supports AHCI compatible controllers having PCI class 1 (mass storage),
155 subclass 6 (SATA) and programming interface 1 (AHCI).
157 Also, in cooperation with atamarvell and atajmicron drivers of ata(4),
158 it supports AHCI part of legacy-PATA + AHCI-SATA combined controllers,
159 such as JMicron JMB36x and Marvell 88SE61xx.
163 driver also supports AHCI devices that act as PCI bridges for
165 using Intel Rapid Storage Technology (RST).
168 device, either one must set the SATA mode in the BIOS to AHCI (from RST),
169 or one must accept the performance with RST enabled due to interrupt sharing.
171 will automatically detect AHCI devices with this extension that are in RST
181 .Bl -tag -width /dev/led/ahcich*.locate
182 .It Pa /dev/led/ahci*.*.act
183 activity LED device nodes
184 .It Pa /dev/led/ahci*.*.fault
185 fault LED device nodes
186 .It Pa /dev/led/ahci*.*.locate
187 locate LED device nodes
191 .It Pa dev.ahcich.X.disable_phy
192 Set to 1 to disable the phy for the drive on channel X.
193 Set to 0 to enable the phy.
194 Useful for turning off troublemakers.
195 Also useful for debugging when you need the ada drive to come and go.
208 driver first appeared in
211 .An Alexander Motin Aq Mt mav@FreeBSD.org