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) support. By default this feature is turned
60 turned off. If the device does !! 60 off.
61 priority feature, writing "1" <<
62 (see ncq_prio_supported). <<
63 <<
64 <<
65 What: /sys/block/*/device/sas_ncq_pr <<
66 Date: Oct, 2016 <<
67 KernelVersion: v4.10 <<
68 Contact: linux-ide@vger.kernel.org <<
69 Description: <<
70 (RW) This is the equivalent of <<
71 file for SATA devices connecte <<
72 (HBA) implementing support for <<
73 This file does not exist if th <<
74 support for the SATA NCQ prior <<
75 device support for this featur <<
76 <<
77 <<
78 What: /sys/block/*/device/ncq_prio_s <<
79 Date: Aug, 2021 <<
80 KernelVersion: v5.15 <<
81 Contact: linux-ide@vger.kernel.org <<
82 Description: <<
83 (RO) Indicates if the device s <<
84 command queueing) priority fea <<
85 <<
86 <<
87 What: /sys/block/*/device/sas_ncq_pr <<
88 Date: Aug, 2021 <<
89 KernelVersion: v5.15 <<
90 Contact: linux-ide@vger.kernel.org <<
91 Description: <<
92 (RO) This is the equivalent of <<
93 file for SATA devices connecte <<
94 (HBA) implementing support for <<
95 This file does not exist if th <<
96 support for the SATA NCQ prior <<
97 device support for this featur <<
98 <<
99 <<
100 What: /sys/block/*/device/cdl_suppor <<
101 Date: May, 2023 <<
102 KernelVersion: v6.5 <<
103 Contact: linux-scsi@vger.kernel.org <<
104 Description: <<
105 (RO) Indicates if the device s <<
106 limits feature found in some A <<
107 <<
108 <<
109 What: /sys/block/*/device/cdl_enable <<
110 Date: May, 2023 <<
111 KernelVersion: v6.5 <<
112 Contact: linux-scsi@vger.kernel.org <<
113 Description: <<
114 (RW) For a device supporting t <<
115 feature, write to the file to <<
116 By default this feature is tur <<
117 Writing "1" to this file enabl <<
118 limits for read and write comm <<
119 the feature on the device. Wri <<
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