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Diffstat (limited to 'Documentation/ABI/testing/sysfs-class-scsi_host')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-scsi_host | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-scsi_host b/Documentation/ABI/testing/sysfs-class-scsi_host new file mode 100644 index 000000000..bafc59fd7 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-scsi_host @@ -0,0 +1,118 @@ +What: /sys/class/scsi_host/hostX/isci_id +Date: June 2011 +Contact: Dave Jiang <dave.jiang@intel.com> +Description: + This file contains the enumerated host ID for the Intel + SCU controller. The Intel(R) C600 Series Chipset SATA/SAS + Storage Control Unit embeds up to two 4-port controllers in + a single PCI device. The controllers are enumerated in order + which usually means the lowest number scsi_host corresponds + with the first controller, but this association is not + guaranteed. The 'isci_id' attribute unambiguously identifies + the controller index: '0' for the first controller, + '1' for the second. + +What: /sys/class/scsi_host/hostX/acciopath_status +Date: November 2013 +Contact: Stephen M. Cameron <scameron@beardog.cce.hp.com> +Description: This file contains the current status of the "SSD Smart Path" + feature of HP Smart Array RAID controllers using the hpsa + driver. SSD Smart Path, when enabled permits the driver to + send i/o requests directly to physical devices that are part + of a logical drive, bypassing the controllers firmware RAID + stack for a performance advantage when possible. A value of + '1' indicates the feature is enabled, and the controller may + use the direct i/o path to physical devices. A value of zero + means the feature is disabled and the controller may not use + the direct i/o path to physical devices. This setting is + controller wide, affecting all configured logical drives on the + controller. This file is readable and writable. + +What: /sys/class/scsi_host/hostX/link_power_management_policy +Date: Oct, 2007 +KernelVersion: v2.6.24 +Contact: linux-ide@vger.kernel.org +Description: + (RW) This parameter allows the user to read and set the link + (interface) power management. + + There are four possible options: + + min_power: Tell the controller to try to make the link use the + least possible power when possible. This may sacrifice some + performance due to increased latency when coming out of lower + power states. + + max_performance: Generally, this means no power management. + Tell the controller to have performance be a priority over power + management. + + medium_power: Tell the controller to enter a lower power state + when possible, but do not enter the lowest power state, thus + improving latency over min_power setting. + + med_power_with_dipm: Identical to the existing medium_power + setting except that it enables dipm (device initiated power + management) on top, which makes it match the Windows IRST (Intel + Rapid Storage Technology) driver settings. This setting is also + close to min_power, except that: + a) It does not use host-initiated slumber mode, but it does + allow device-initiated slumber + b) It does not enable low power device sleep mode (DevSlp). + +What: /sys/class/scsi_host/hostX/em_message +What: /sys/class/scsi_host/hostX/em_message_type +Date: Jun, 2008 +KernelVersion: v2.6.27 +Contact: linux-ide@vger.kernel.org +Description: + em_message: (RW) Enclosure management support. For the LED + protocol, writes and reads correspond to the LED message format + as defined in the AHCI spec. + + The user must turn sw_activity (under /sys/block/*/device/) OFF + it they wish to control the activity LED via the em_message + file. + + em_message_type: (RO) Displays the current enclosure management + protocol that is being used by the driver (for eg. LED, SAF-TE, + SES-2, SGPIO etc). + +What: /sys/class/scsi_host/hostX/ahci_port_cmd +What: /sys/class/scsi_host/hostX/ahci_host_caps +What: /sys/class/scsi_host/hostX/ahci_host_cap2 +Date: Mar, 2010 +KernelVersion: v2.6.35 +Contact: linux-ide@vger.kernel.org +Description: + [to be documented] + +What: /sys/class/scsi_host/hostX/ahci_host_version +Date: Mar, 2010 +KernelVersion: v2.6.35 +Contact: linux-ide@vger.kernel.org +Description: + (RO) Display the version of the AHCI spec implemented by the + host. + +What: /sys/class/scsi_host/hostX/em_buffer +Date: Apr, 2010 +KernelVersion: v2.6.35 +Contact: linux-ide@vger.kernel.org +Description: + (RW) Allows access to AHCI EM (enclosure management) buffer + directly if the host supports EM. + + For eg. the AHCI driver supports SGPIO EM messages but the + SATA/AHCI specs do not define the SGPIO message format of the EM + buffer. Different hardware(HW) vendors may have different + definitions. With the em_buffer attribute, this issue can be + solved by allowing HW vendors to provide userland drivers and + tools for their SGPIO initiators. + +What: /sys/class/scsi_host/hostX/em_message_supported +Date: Oct, 2009 +KernelVersion: v2.6.39 +Contact: linux-ide@vger.kernel.org +Description: + (RO) Displays supported enclosure management message types. |