^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) What: /sys/devices/.../online
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) Date: April 2013
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) The /sys/devices/.../online attribute is only present for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) devices whose bus types provide .online() and .offline()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) callbacks. The number read from it (0 or 1) reflects the value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) of the device's 'offline' field. If that number is 1 and '0'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) (or 'n', or 'N') is written to this file, the device bus type's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) .offline() callback is executed for the device and (if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) successful) its 'offline' field is updated accordingly. In
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) turn, if that number is 0 and '1' (or 'y', or 'Y') is written to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) this file, the device bus type's .online() callback is executed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) for the device and (if successful) its 'offline' field is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) updated as appropriate.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) After a successful execution of the bus type's .offline()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) callback the device cannot be used for any purpose until either
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) it is removed (i.e. device_del() is called for it), or its bus
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) type's .online() is exeucted successfully.