0001 What: /sys/block/*/device/sw_activity
0002 Date: Jun, 2008
0003 KernelVersion: v2.6.27
0004 Contact: linux-ide@vger.kernel.org
0005 Description:
0006 (RW) Used by drivers which support software controlled activity
0007 LEDs.
0008
0009 It has the following valid values:
0010
0011 == ========================================================
0012 0 OFF - the LED is not activated on activity
0013 1 BLINK_ON - the LED blinks on every 10ms when activity is
0014 detected.
0015 2 BLINK_OFF - the LED is on when idle, and blinks off
0016 every 10ms when activity is detected.
0017 == ========================================================
0018
0019 Note that the user must turn sw_activity OFF it they wish to
0020 control the activity LED via the em_message file.
0021
0022
0023 What: /sys/block/*/device/unload_heads
0024 Date: Sep, 2008
0025 KernelVersion: v2.6.28
0026 Contact: linux-ide@vger.kernel.org
0027 Description:
0028 (RW) Hard disk shock protection
0029
0030 Writing an integer value to this file will take the heads of the
0031 respective drive off the platter and block all I/O operations
0032 for the specified number of milliseconds.
0033
0034 - If the device does not support the unload heads feature,
0035 access is denied with -EOPNOTSUPP.
0036 - The maximal value accepted for a timeout is 30000
0037 milliseconds.
0038 - A previously set timeout can be cancelled and disk can resume
0039 normal operation immediately by specifying a timeout of 0.
0040 - Some hard drives only comply with an earlier version of the
0041 ATA standard, but support the unload feature nonetheless.
0042 There is no safe way Linux can detect these devices, so this
0043 is not enabled by default. If it is known that your device
0044 does support the unload feature, then you can tell the kernel
0045 to enable it by writing -1. It can be disabled again by
0046 writing -2.
0047 - Values below -2 are rejected with -EINVAL
0048
0049 For more information, see
0050 Documentation/admin-guide/laptops/disk-shock-protection.rst
0051
0052
0053 What: /sys/block/*/device/ncq_prio_enable
0054 Date: Oct, 2016
0055 KernelVersion: v4.10
0056 Contact: linux-ide@vger.kernel.org
0057 Description:
0058 (RW) Write to the file to turn on or off the SATA NCQ (native
0059 command queueing) priority support. By default this feature is
0060 turned off. If the device does not support the SATA NCQ
0061 priority feature, writing "1" to this file results in an error
0062 (see ncq_prio_supported).
0063
0064
0065 What: /sys/block/*/device/sas_ncq_prio_enable
0066 Date: Oct, 2016
0067 KernelVersion: v4.10
0068 Contact: linux-ide@vger.kernel.org
0069 Description:
0070 (RW) This is the equivalent of the ncq_prio_enable attribute
0071 file for SATA devices connected to a SAS host-bus-adapter
0072 (HBA) implementing support for the SATA NCQ priority feature.
0073 This file does not exist if the HBA driver does not implement
0074 support for the SATA NCQ priority feature, regardless of the
0075 device support for this feature (see sas_ncq_prio_supported).
0076
0077
0078 What: /sys/block/*/device/ncq_prio_supported
0079 Date: Aug, 2021
0080 KernelVersion: v5.15
0081 Contact: linux-ide@vger.kernel.org
0082 Description:
0083 (RO) Indicates if the device supports the SATA NCQ (native
0084 command queueing) priority feature.
0085
0086
0087 What: /sys/block/*/device/sas_ncq_prio_supported
0088 Date: Aug, 2021
0089 KernelVersion: v5.15
0090 Contact: linux-ide@vger.kernel.org
0091 Description:
0092 (RO) This is the equivalent of the ncq_prio_supported attribute
0093 file for SATA devices connected to a SAS host-bus-adapter
0094 (HBA) implementing support for the SATA NCQ priority feature.
0095 This file does not exist if the HBA driver does not implement
0096 support for the SATA NCQ priority feature, regardless of the
0097 device support for this feature.
