1 What: /sys/bus/usb/devices/.../power
2 Date: May 2007
3 KernelVersion: 2.6.23
4 Contact: Alan Stern <stern@rowland.harva
5 Description:
6 USB device directories can con
7 The file holds a boolean value
8 not the "USB-Persist" facility
9 hubs this facility is always e
10 directories will not contain t
11
12 For more information, see Docu
13
14 What: /sys/bus/usb/devices/.../power
15 Date: March 2007
16 KernelVersion: 2.6.21
17 Contact: Alan Stern <stern@rowland.harva
18 Description:
19 Each USB device directory will
20 power/autosuspend. This file
21 the device must be idle before
22 0 means the device will be aut
23 possible. Negative values wil
24 being autosuspended at all, an
25 will resume the device if it i
26
27 The autosuspend delay for newl
28 the value of the usbcore.autos
29
30 What: /sys/bus/usb/device/.../power/
31 Date: January 2008
32 KernelVersion: 2.6.25
33 Contact: Sarah Sharp <sarah.a.sharp@inte
34 Description:
35 If CONFIG_PM is enabled, then
36 it returns the total time (in
37 connected to the machine. Thi
38 Users:
39 PowerTOP <powertop@lists.01.org
40 https://01.org/powertop/
41
42 What: /sys/bus/usb/device/.../power/
43 Date: January 2008
44 KernelVersion: 2.6.25
45 Contact: Sarah Sharp <sarah.a.sharp@inte
46 Description:
47 If CONFIG_PM is enabled, then
48 it returns the total time (in
49 active, i.e. not in a suspende
50
51 Tools can use this file and th
52 compute the percentage of time
53 For example::
54
55 echo $((100 * `cat active_du
56
57 will give an integer percentag
58 account for counter wrap.
59 Users:
60 PowerTOP <powertop@lists.01.org
61 https://01.org/powertop/
62
63 What: /sys/bus/usb/devices/<busnum>-
64 Date: January 2008
65 KernelVersion: 2.6.27
66 Contact: Sarah Sharp <sarah.a.sharp@inte
67 Description:
68 When read, this file returns 1
69 for this interface supports au
70 returns 1 if no driver has cla
71 unclaimed interface will not s
72 autosuspended if all other int
73 The file returns 0 if autosusp
74 added to the driver.
75 Users:
76 USB PM tool
77 git://git.moblin.org/users/sar
78
79 What: /sys/bus/usb/device/.../avoid_
80 Date: December 2009
81 Contact: Oliver Neukum <oliver@neukum.or
82 Description:
83 Writing 1 to this file tells t
84 device will morph into another
85 Drivers will not use reset for
86 such devices.
87 Users:
88 usb_modeswitch
89
90 What: /sys/bus/usb/devices/.../devnu
91 KernelVersion: since at least 2.6.18
92 Description:
93 Device address on the USB bus.
94 Users:
95 libusb
96
97 What: /sys/bus/usb/devices/.../bConf
98 KernelVersion: since at least 2.6.18
99 Description:
100 bConfigurationValue of the *ac
101 device. Writing 0 or -1 to bCo
102 active configuration (unconfig
103 another value will change the
104
105 Note that some devices, in vio
106 configuration with a value equ
107 bConfigurationValue for these
108 configuration, rather then unc
109
110 Writing -1 will always unconfi
111 Users:
112 libusb
113
114 What: /sys/bus/usb/devices/.../busnu
115 KernelVersion: 2.6.22
116 Description:
117 Bus-number of the USB-bus the
118 Users:
119 libusb
120
121 What: /sys/bus/usb/devices/.../descr
122 KernelVersion: 2.6.26
123 Description:
124 Binary file containing cached
125 binary data consists of the de
126 descriptors for each configura
127 Note that the wTotalLength of
128 be trusted, as the device may
129 than it advertises. The bLengt
130 can be trusted, and can be use
131 descriptor at a time until the
132 All descriptors read from this
133 Users:
134 libusb
135
136 What: /sys/bus/usb/devices/.../speed
137 KernelVersion: since at least 2.6.18
138 Description:
139 Speed the device is connected
140 Mbit / second. IE one of 1.5 /
141 Users:
142 libusb
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