162306a36Sopenharmony_ciWhat: /sys/devices/.../online 262306a36Sopenharmony_ciDate: April 2013 362306a36Sopenharmony_ciContact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 462306a36Sopenharmony_ciDescription: 562306a36Sopenharmony_ci The /sys/devices/.../online attribute is only present for 662306a36Sopenharmony_ci devices whose bus types provide .online() and .offline() 762306a36Sopenharmony_ci callbacks. The number read from it (0 or 1) reflects the value 862306a36Sopenharmony_ci of the device's 'offline' field. If that number is 1 and '0' 962306a36Sopenharmony_ci (or 'n', or 'N') is written to this file, the device bus type's 1062306a36Sopenharmony_ci .offline() callback is executed for the device and (if 1162306a36Sopenharmony_ci successful) its 'offline' field is updated accordingly. In 1262306a36Sopenharmony_ci turn, if that number is 0 and '1' (or 'y', or 'Y') is written to 1362306a36Sopenharmony_ci this file, the device bus type's .online() callback is executed 1462306a36Sopenharmony_ci for the device and (if successful) its 'offline' field is 1562306a36Sopenharmony_ci updated as appropriate. 1662306a36Sopenharmony_ci 1762306a36Sopenharmony_ci After a successful execution of the bus type's .offline() 1862306a36Sopenharmony_ci callback the device cannot be used for any purpose until either 1962306a36Sopenharmony_ci it is removed (i.e. device_del() is called for it), or its bus 2062306a36Sopenharmony_ci type's .online() is executed successfully. 21