1 What: /sys/devices/.../online 1 What: /sys/devices/.../online
2 Date: April 2013 2 Date: April 2013
3 Contact: Rafael J. Wysocki <rafael.j.wys 3 Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
4 Description: 4 Description:
5 The /sys/devices/.../online at 5 The /sys/devices/.../online attribute is only present for
6 devices whose bus types provid 6 devices whose bus types provide .online() and .offline()
7 callbacks. The number read fr 7 callbacks. The number read from it (0 or 1) reflects the value
8 of the device's 'offline' fiel 8 of the device's 'offline' field. If that number is 1 and '0'
9 (or 'n', or 'N') is written to 9 (or 'n', or 'N') is written to this file, the device bus type's
10 .offline() callback is execute 10 .offline() callback is executed for the device and (if
11 successful) its 'offline' fiel 11 successful) its 'offline' field is updated accordingly. In
12 turn, if that number is 0 and 12 turn, if that number is 0 and '1' (or 'y', or 'Y') is written to
13 this file, the device bus type 13 this file, the device bus type's .online() callback is executed
14 for the device and (if success 14 for the device and (if successful) its 'offline' field is
15 updated as appropriate. 15 updated as appropriate.
16 16
17 After a successful execution o 17 After a successful execution of the bus type's .offline()
18 callback the device cannot be 18 callback the device cannot be used for any purpose until either
19 it is removed (i.e. device_del 19 it is removed (i.e. device_del() is called for it), or its bus
20 type's .online() is executed s 20 type's .online() is executed successfully.
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