1 What: /sys/block/*/device/sw_activit 1 What: /sys/block/*/device/sw_activity
2 Date: Jun, 2008 2 Date: Jun, 2008
3 KernelVersion: v2.6.27 3 KernelVersion: v2.6.27
4 Contact: linux-ide@vger.kernel.org 4 Contact: linux-ide@vger.kernel.org
5 Description: 5 Description:
6 (RW) Used by drivers which sup 6 (RW) Used by drivers which support software controlled activity
7 LEDs. 7 LEDs.
8 8
9 It has the following valid val 9 It has the following valid values:
10 10
11 == ====================== 11 == ========================================================
12 0 OFF - the LED is not a 12 0 OFF - the LED is not activated on activity
13 1 BLINK_ON - the LED bli 13 1 BLINK_ON - the LED blinks on every 10ms when activity is
14 detected. 14 detected.
15 2 BLINK_OFF - the LED is 15 2 BLINK_OFF - the LED is on when idle, and blinks off
16 every 10ms when activi 16 every 10ms when activity is detected.
17 == ====================== 17 == ========================================================
18 18
19 Note that the user must turn s 19 Note that the user must turn sw_activity OFF it they wish to
20 control the activity LED via t 20 control the activity LED via the em_message file.
21 21
22 22
23 What: /sys/block/*/device/unload_hea 23 What: /sys/block/*/device/unload_heads
24 Date: Sep, 2008 24 Date: Sep, 2008
25 KernelVersion: v2.6.28 25 KernelVersion: v2.6.28
26 Contact: linux-ide@vger.kernel.org 26 Contact: linux-ide@vger.kernel.org
27 Description: 27 Description:
28 (RW) Hard disk shock protectio 28 (RW) Hard disk shock protection
29 29
30 Writing an integer value to th 30 Writing an integer value to this file will take the heads of the
31 respective drive off the platt 31 respective drive off the platter and block all I/O operations
32 for the specified number of mi 32 for the specified number of milliseconds.
33 33
34 - If the device does not suppo 34 - If the device does not support the unload heads feature,
35 access is denied with -EOPNO 35 access is denied with -EOPNOTSUPP.
36 - The maximal value accepted f 36 - The maximal value accepted for a timeout is 30000
37 milliseconds. 37 milliseconds.
38 - A previously set timeout can 38 - A previously set timeout can be cancelled and disk can resume
39 normal operation immediately 39 normal operation immediately by specifying a timeout of 0.
40 - Some hard drives only comply 40 - Some hard drives only comply with an earlier version of the
41 ATA standard, but support th 41 ATA standard, but support the unload feature nonetheless.
42 There is no safe way Linux c 42 There is no safe way Linux can detect these devices, so this
43 is not enabled by default. I 43 is not enabled by default. If it is known that your device
44 does support the unload feat 44 does support the unload feature, then you can tell the kernel
45 to enable it by writing -1. 45 to enable it by writing -1. It can be disabled again by
46 writing -2. 46 writing -2.
47 - Values below -2 are rejected 47 - Values below -2 are rejected with -EINVAL
48 48
49 For more information, see 49 For more information, see
50 Documentation/admin-guide/lapt 50 Documentation/admin-guide/laptops/disk-shock-protection.rst
51 51
52 52
53 What: /sys/block/*/device/ncq_prio_e 53 What: /sys/block/*/device/ncq_prio_enable
54 Date: Oct, 2016 54 Date: Oct, 2016
55 KernelVersion: v4.10 55 KernelVersion: v4.10
56 Contact: linux-ide@vger.kernel.org 56 Contact: linux-ide@vger.kernel.org
57 Description: 57 Description:
58 (RW) Write to the file to turn 58 (RW) Write to the file to turn on or off the SATA NCQ (native
59 command queueing) priority sup 59 command queueing) priority support. By default this feature is
60 turned off. If the device does 60 turned off. If the device does not support the SATA NCQ
61 priority feature, writing "1" 61 priority feature, writing "1" to this file results in an error
62 (see ncq_prio_supported). 62 (see ncq_prio_supported).
63 63
64 64
65 What: /sys/block/*/device/sas_ncq_pr 65 What: /sys/block/*/device/sas_ncq_prio_enable
66 Date: Oct, 2016 66 Date: Oct, 2016
67 KernelVersion: v4.10 67 KernelVersion: v4.10
68 Contact: linux-ide@vger.kernel.org 68 Contact: linux-ide@vger.kernel.org
69 Description: 69 Description:
70 (RW) This is the equivalent of 70 (RW) This is the equivalent of the ncq_prio_enable attribute
71 file for SATA devices connecte 71 file for SATA devices connected to a SAS host-bus-adapter
72 (HBA) implementing support for 72 (HBA) implementing support for the SATA NCQ priority feature.
73 This file does not exist if th 73 This file does not exist if the HBA driver does not implement
74 support for the SATA NCQ prior 74 support for the SATA NCQ priority feature, regardless of the
75 device support for this featur 75 device support for this feature (see sas_ncq_prio_supported).
76 76
77 77
78 What: /sys/block/*/device/ncq_prio_s 78 What: /sys/block/*/device/ncq_prio_supported
79 Date: Aug, 2021 79 Date: Aug, 2021
80 KernelVersion: v5.15 80 KernelVersion: v5.15
81 Contact: linux-ide@vger.kernel.org 81 Contact: linux-ide@vger.kernel.org
82 Description: 82 Description:
83 (RO) Indicates if the device s 83 (RO) Indicates if the device supports the SATA NCQ (native
84 command queueing) priority fea 84 command queueing) priority feature.
85 85
86 86
87 What: /sys/block/*/device/sas_ncq_pr 87 What: /sys/block/*/device/sas_ncq_prio_supported
88 Date: Aug, 2021 88 Date: Aug, 2021
89 KernelVersion: v5.15 89 KernelVersion: v5.15
90 Contact: linux-ide@vger.kernel.org 90 Contact: linux-ide@vger.kernel.org
91 Description: 91 Description:
92 (RO) This is the equivalent of 92 (RO) This is the equivalent of the ncq_prio_supported attribute
93 file for SATA devices connecte 93 file for SATA devices connected to a SAS host-bus-adapter
94 (HBA) implementing support for 94 (HBA) implementing support for the SATA NCQ priority feature.
95 This file does not exist if th 95 This file does not exist if the HBA driver does not implement
96 support for the SATA NCQ prior 96 support for the SATA NCQ priority feature, regardless of the
97 device support for this featur 97 device support for this feature.
98 98
99 99
100 What: /sys/block/*/device/cdl_suppor 100 What: /sys/block/*/device/cdl_supported
101 Date: May, 2023 101 Date: May, 2023
102 KernelVersion: v6.5 102 KernelVersion: v6.5
103 Contact: linux-scsi@vger.kernel.org 103 Contact: linux-scsi@vger.kernel.org
104 Description: 104 Description:
105 (RO) Indicates if the device s 105 (RO) Indicates if the device supports the command duration
106 limits feature found in some A 106 limits feature found in some ATA and SCSI devices.
107 107
108 108
109 What: /sys/block/*/device/cdl_enable 109 What: /sys/block/*/device/cdl_enable
110 Date: May, 2023 110 Date: May, 2023
111 KernelVersion: v6.5 111 KernelVersion: v6.5
112 Contact: linux-scsi@vger.kernel.org 112 Contact: linux-scsi@vger.kernel.org
113 Description: 113 Description:
114 (RW) For a device supporting t 114 (RW) For a device supporting the command duration limits
115 feature, write to the file to 115 feature, write to the file to turn on or off the feature.
116 By default this feature is tur 116 By default this feature is turned off.
117 Writing "1" to this file enabl 117 Writing "1" to this file enables the use of command duration
118 limits for read and write comm 118 limits for read and write commands in the kernel and turns on
119 the feature on the device. Wri 119 the feature on the device. Writing "0" disables the feature.
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