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 11*34433332SMauro Carvalho Chehab == ======================================================== 120a65e125SAishwarya Pant 0 OFF - the LED is not activated on activity 130a65e125SAishwarya Pant 1 BLINK_ON - the LED blinks on every 10ms when activity is 140a65e125SAishwarya Pant detected. 150a65e125SAishwarya Pant 2 BLINK_OFF - the LED is on when idle, and blinks off 160a65e125SAishwarya Pant every 10ms when activity is detected. 17*34433332SMauro Carvalho Chehab == ======================================================== 180a65e125SAishwarya Pant 190a65e125SAishwarya Pant Note that the user must turn sw_activity OFF it they wish to 200a65e125SAishwarya Pant control the activity LED via the em_message file. 210a65e125SAishwarya Pant 220a65e125SAishwarya Pant 230a65e125SAishwarya PantWhat: /sys/block/*/device/unload_heads 240a65e125SAishwarya PantDate: Sep, 2008 250a65e125SAishwarya PantKernelVersion: v2.6.28 260a65e125SAishwarya PantContact: linux-ide@vger.kernel.org 270a65e125SAishwarya PantDescription: 280a65e125SAishwarya Pant (RW) Hard disk shock protection 290a65e125SAishwarya Pant 300a65e125SAishwarya Pant Writing an integer value to this file will take the heads of the 310a65e125SAishwarya Pant respective drive off the platter and block all I/O operations 320a65e125SAishwarya Pant for the specified number of milliseconds. 330a65e125SAishwarya Pant 340a65e125SAishwarya Pant - If the device does not support the unload heads feature, 350a65e125SAishwarya Pant access is denied with -EOPNOTSUPP. 360a65e125SAishwarya Pant - The maximal value accepted for a timeout is 30000 370a65e125SAishwarya Pant milliseconds. 380a65e125SAishwarya Pant - A previously set timeout can be cancelled and disk can resume 390a65e125SAishwarya Pant normal operation immediately by specifying a timeout of 0. 400a65e125SAishwarya Pant - Some hard drives only comply with an earlier version of the 410a65e125SAishwarya Pant ATA standard, but support the unload feature nonetheless. 420a65e125SAishwarya Pant There is no safe way Linux can detect these devices, so this 430a65e125SAishwarya Pant is not enabled by default. If it is known that your device 440a65e125SAishwarya Pant does support the unload feature, then you can tell the kernel 450a65e125SAishwarya Pant to enable it by writing -1. It can be disabled again by 460a65e125SAishwarya Pant writing -2. 470a65e125SAishwarya Pant - Values below -2 are rejected with -EINVAL 480a65e125SAishwarya Pant 490a65e125SAishwarya Pant For more information, see 509e1cbedeSMauro Carvalho Chehab Documentation/admin-guide/laptops/disk-shock-protection.rst 510a65e125SAishwarya Pant 520a65e125SAishwarya Pant 530a65e125SAishwarya PantWhat: /sys/block/*/device/ncq_prio_enable 540a65e125SAishwarya PantDate: Oct, 2016 550a65e125SAishwarya PantKernelVersion: v4.10 560a65e125SAishwarya PantContact: linux-ide@vger.kernel.org 570a65e125SAishwarya PantDescription: 580a65e125SAishwarya Pant (RW) Write to the file to turn on or off the SATA ncq (native 590a65e125SAishwarya Pant command queueing) support. By default this feature is turned 600a65e125SAishwarya Pant off. 61