0001 What: /sys/devices/.../online
0002 Date: April 2013
0003 Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
0004 Description:
0005 The /sys/devices/.../online attribute is only present for
0006 devices whose bus types provide .online() and .offline()
0007 callbacks. The number read from it (0 or 1) reflects the value
0008 of the device's 'offline' field. If that number is 1 and '0'
0009 (or 'n', or 'N') is written to this file, the device bus type's
0010 .offline() callback is executed for the device and (if
0011 successful) its 'offline' field is updated accordingly. In
0012 turn, if that number is 0 and '1' (or 'y', or 'Y') is written to
0013 this file, the device bus type's .online() callback is executed
0014 for the device and (if successful) its 'offline' field is
0015 updated as appropriate.
0016
0017 After a successful execution of the bus type's .offline()
0018 callback the device cannot be used for any purpose until either
0019 it is removed (i.e. device_del() is called for it), or its bus
0020 type's .online() is exeucted successfully.
