1*4882a593SmuzhiyunWhat: /sys/devices/.../online 2*4882a593SmuzhiyunDate: April 2013 3*4882a593SmuzhiyunContact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 4*4882a593SmuzhiyunDescription: 5*4882a593Smuzhiyun The /sys/devices/.../online attribute is only present for 6*4882a593Smuzhiyun devices whose bus types provide .online() and .offline() 7*4882a593Smuzhiyun callbacks. The number read from it (0 or 1) reflects the value 8*4882a593Smuzhiyun of the device's 'offline' field. If that number is 1 and '0' 9*4882a593Smuzhiyun (or 'n', or 'N') is written to this file, the device bus type's 10*4882a593Smuzhiyun .offline() callback is executed for the device and (if 11*4882a593Smuzhiyun successful) its 'offline' field is updated accordingly. In 12*4882a593Smuzhiyun turn, if that number is 0 and '1' (or 'y', or 'Y') is written to 13*4882a593Smuzhiyun this file, the device bus type's .online() callback is executed 14*4882a593Smuzhiyun for the device and (if successful) its 'offline' field is 15*4882a593Smuzhiyun updated as appropriate. 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun After a successful execution of the bus type's .offline() 18*4882a593Smuzhiyun callback the device cannot be used for any purpose until either 19*4882a593Smuzhiyun it is removed (i.e. device_del() is called for it), or its bus 20*4882a593Smuzhiyun type's .online() is exeucted successfully. 21