1*0a65e125SAishwarya PantWhat: /sys/block/*/device/sw_activity 2*0a65e125SAishwarya PantDate: Jun, 2008 3*0a65e125SAishwarya PantKernelVersion: v2.6.27 4*0a65e125SAishwarya PantContact: linux-ide@vger.kernel.org 5*0a65e125SAishwarya PantDescription: 6*0a65e125SAishwarya Pant (RW) Used by drivers which support software controlled activity 7*0a65e125SAishwarya Pant LEDs. 8*0a65e125SAishwarya Pant 9*0a65e125SAishwarya Pant It has the following valid values: 10*0a65e125SAishwarya Pant 11*0a65e125SAishwarya Pant 0 OFF - the LED is not activated on activity 12*0a65e125SAishwarya Pant 1 BLINK_ON - the LED blinks on every 10ms when activity is 13*0a65e125SAishwarya Pant detected. 14*0a65e125SAishwarya Pant 2 BLINK_OFF - the LED is on when idle, and blinks off 15*0a65e125SAishwarya Pant every 10ms when activity is detected. 16*0a65e125SAishwarya Pant 17*0a65e125SAishwarya Pant Note that the user must turn sw_activity OFF it they wish to 18*0a65e125SAishwarya Pant control the activity LED via the em_message file. 19*0a65e125SAishwarya Pant 20*0a65e125SAishwarya Pant 21*0a65e125SAishwarya PantWhat: /sys/block/*/device/unload_heads 22*0a65e125SAishwarya PantDate: Sep, 2008 23*0a65e125SAishwarya PantKernelVersion: v2.6.28 24*0a65e125SAishwarya PantContact: linux-ide@vger.kernel.org 25*0a65e125SAishwarya PantDescription: 26*0a65e125SAishwarya Pant (RW) Hard disk shock protection 27*0a65e125SAishwarya Pant 28*0a65e125SAishwarya Pant Writing an integer value to this file will take the heads of the 29*0a65e125SAishwarya Pant respective drive off the platter and block all I/O operations 30*0a65e125SAishwarya Pant for the specified number of milliseconds. 31*0a65e125SAishwarya Pant 32*0a65e125SAishwarya Pant - If the device does not support the unload heads feature, 33*0a65e125SAishwarya Pant access is denied with -EOPNOTSUPP. 34*0a65e125SAishwarya Pant - The maximal value accepted for a timeout is 30000 35*0a65e125SAishwarya Pant milliseconds. 36*0a65e125SAishwarya Pant - A previously set timeout can be cancelled and disk can resume 37*0a65e125SAishwarya Pant normal operation immediately by specifying a timeout of 0. 38*0a65e125SAishwarya Pant - Some hard drives only comply with an earlier version of the 39*0a65e125SAishwarya Pant ATA standard, but support the unload feature nonetheless. 40*0a65e125SAishwarya Pant There is no safe way Linux can detect these devices, so this 41*0a65e125SAishwarya Pant is not enabled by default. If it is known that your device 42*0a65e125SAishwarya Pant does support the unload feature, then you can tell the kernel 43*0a65e125SAishwarya Pant to enable it by writing -1. It can be disabled again by 44*0a65e125SAishwarya Pant writing -2. 45*0a65e125SAishwarya Pant - Values below -2 are rejected with -EINVAL 46*0a65e125SAishwarya Pant 47*0a65e125SAishwarya Pant For more information, see 48*0a65e125SAishwarya Pant Documentation/laptops/disk-shock-protection.txt 49*0a65e125SAishwarya Pant 50*0a65e125SAishwarya Pant 51*0a65e125SAishwarya PantWhat: /sys/block/*/device/ncq_prio_enable 52*0a65e125SAishwarya PantDate: Oct, 2016 53*0a65e125SAishwarya PantKernelVersion: v4.10 54*0a65e125SAishwarya PantContact: linux-ide@vger.kernel.org 55*0a65e125SAishwarya PantDescription: 56*0a65e125SAishwarya Pant (RW) Write to the file to turn on or off the SATA ncq (native 57*0a65e125SAishwarya Pant command queueing) support. By default this feature is turned 58*0a65e125SAishwarya Pant off. 59