| 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. |