| What: /sys/block/*/device/sw_activity | |
| Date: Jun, 2008 | |
| KernelVersion: v2.6.27 | |
| Contact: linux-ide@vger.kernel.org | |
| Description: | |
| (RW) Used by drivers which support software controlled activity | |
| LEDs. | |
| It has the following valid values: | |
| 0 OFF - the LED is not activated on activity | |
| 1 BLINK_ON - the LED blinks on every 10ms when activity is | |
| detected. | |
| 2 BLINK_OFF - the LED is on when idle, and blinks off | |
| every 10ms when activity is detected. | |
| Note that the user must turn sw_activity OFF it they wish to | |
| control the activity LED via the em_message file. | |
| What: /sys/block/*/device/unload_heads | |
| Date: Sep, 2008 | |
| KernelVersion: v2.6.28 | |
| Contact: linux-ide@vger.kernel.org | |
| Description: | |
| (RW) Hard disk shock protection | |
| Writing an integer value to this file will take the heads of the | |
| respective drive off the platter and block all I/O operations | |
| for the specified number of milliseconds. | |
| - If the device does not support the unload heads feature, | |
| access is denied with -EOPNOTSUPP. | |
| - The maximal value accepted for a timeout is 30000 | |
| milliseconds. | |
| - A previously set timeout can be cancelled and disk can resume | |
| normal operation immediately by specifying a timeout of 0. | |
| - Some hard drives only comply with an earlier version of the | |
| ATA standard, but support the unload feature nonetheless. | |
| There is no safe way Linux can detect these devices, so this | |
| is not enabled by default. If it is known that your device | |
| does support the unload feature, then you can tell the kernel | |
| to enable it by writing -1. It can be disabled again by | |
| writing -2. | |
| - Values below -2 are rejected with -EINVAL | |
| For more information, see | |
| Documentation/laptops/disk-shock-protection.txt | |
| What: /sys/block/*/device/ncq_prio_enable | |
| Date: Oct, 2016 | |
| KernelVersion: v4.10 | |
| Contact: linux-ide@vger.kernel.org | |
| Description: | |
| (RW) Write to the file to turn on or off the SATA ncq (native | |
| command queueing) support. By default this feature is turned | |
| off. |