10a65e125SAishwarya PantWhat: /sys/block/*/device/sw_activity 20a65e125SAishwarya PantDate: Jun, 2008 30a65e125SAishwarya PantKernelVersion: v2.6.27 40a65e125SAishwarya PantContact: linux-ide@vger.kernel.org 50a65e125SAishwarya PantDescription: 60a65e125SAishwarya Pant (RW) Used by drivers which support software controlled activity 70a65e125SAishwarya Pant LEDs. 80a65e125SAishwarya Pant 90a65e125SAishwarya Pant It has the following valid values: 100a65e125SAishwarya Pant 110a65e125SAishwarya Pant 0 OFF - the LED is not activated on activity 120a65e125SAishwarya Pant 1 BLINK_ON - the LED blinks on every 10ms when activity is 130a65e125SAishwarya Pant detected. 140a65e125SAishwarya Pant 2 BLINK_OFF - the LED is on when idle, and blinks off 150a65e125SAishwarya Pant every 10ms when activity is detected. 160a65e125SAishwarya Pant 170a65e125SAishwarya Pant Note that the user must turn sw_activity OFF it they wish to 180a65e125SAishwarya Pant control the activity LED via the em_message file. 190a65e125SAishwarya Pant 200a65e125SAishwarya Pant 210a65e125SAishwarya PantWhat: /sys/block/*/device/unload_heads 220a65e125SAishwarya PantDate: Sep, 2008 230a65e125SAishwarya PantKernelVersion: v2.6.28 240a65e125SAishwarya PantContact: linux-ide@vger.kernel.org 250a65e125SAishwarya PantDescription: 260a65e125SAishwarya Pant (RW) Hard disk shock protection 270a65e125SAishwarya Pant 280a65e125SAishwarya Pant Writing an integer value to this file will take the heads of the 290a65e125SAishwarya Pant respective drive off the platter and block all I/O operations 300a65e125SAishwarya Pant for the specified number of milliseconds. 310a65e125SAishwarya Pant 320a65e125SAishwarya Pant - If the device does not support the unload heads feature, 330a65e125SAishwarya Pant access is denied with -EOPNOTSUPP. 340a65e125SAishwarya Pant - The maximal value accepted for a timeout is 30000 350a65e125SAishwarya Pant milliseconds. 360a65e125SAishwarya Pant - A previously set timeout can be cancelled and disk can resume 370a65e125SAishwarya Pant normal operation immediately by specifying a timeout of 0. 380a65e125SAishwarya Pant - Some hard drives only comply with an earlier version of the 390a65e125SAishwarya Pant ATA standard, but support the unload feature nonetheless. 400a65e125SAishwarya Pant There is no safe way Linux can detect these devices, so this 410a65e125SAishwarya Pant is not enabled by default. If it is known that your device 420a65e125SAishwarya Pant does support the unload feature, then you can tell the kernel 430a65e125SAishwarya Pant to enable it by writing -1. It can be disabled again by 440a65e125SAishwarya Pant writing -2. 450a65e125SAishwarya Pant - Values below -2 are rejected with -EINVAL 460a65e125SAishwarya Pant 470a65e125SAishwarya Pant For more information, see 48*9e1cbedeSMauro Carvalho Chehab Documentation/admin-guide/laptops/disk-shock-protection.rst 490a65e125SAishwarya Pant 500a65e125SAishwarya Pant 510a65e125SAishwarya PantWhat: /sys/block/*/device/ncq_prio_enable 520a65e125SAishwarya PantDate: Oct, 2016 530a65e125SAishwarya PantKernelVersion: v4.10 540a65e125SAishwarya PantContact: linux-ide@vger.kernel.org 550a65e125SAishwarya PantDescription: 560a65e125SAishwarya Pant (RW) Write to the file to turn on or off the SATA ncq (native 570a65e125SAishwarya Pant command queueing) support. By default this feature is turned 580a65e125SAishwarya Pant off. 59