1*4f3549d7SRafael J. WysockiWhat: /sys/devices/.../online 2*4f3549d7SRafael J. WysockiDate: April 2013 3*4f3549d7SRafael J. WysockiContact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 4*4f3549d7SRafael J. WysockiDescription: 5*4f3549d7SRafael J. Wysocki The /sys/devices/.../online attribute is only present for 6*4f3549d7SRafael J. Wysocki devices whose bus types provide .online() and .offline() 7*4f3549d7SRafael J. Wysocki callbacks. The number read from it (0 or 1) reflects the value 8*4f3549d7SRafael J. Wysocki of the device's 'offline' field. If that number is 1 and '0' 9*4f3549d7SRafael J. Wysocki (or 'n', or 'N') is written to this file, the device bus type's 10*4f3549d7SRafael J. Wysocki .offline() callback is executed for the device and (if 11*4f3549d7SRafael J. Wysocki successful) its 'offline' field is updated accordingly. In 12*4f3549d7SRafael J. Wysocki turn, if that number is 0 and '1' (or 'y', or 'Y') is written to 13*4f3549d7SRafael J. Wysocki this file, the device bus type's .online() callback is executed 14*4f3549d7SRafael J. Wysocki for the device and (if successful) its 'offline' field is 15*4f3549d7SRafael J. Wysocki updated as appropriate. 16*4f3549d7SRafael J. Wysocki 17*4f3549d7SRafael J. Wysocki After a successful execution of the bus type's .offline() 18*4f3549d7SRafael J. Wysocki callback the device cannot be used for any purpose until either 19*4f3549d7SRafael J. Wysocki it is removed (i.e. device_del() is called for it), or its bus 20*4f3549d7SRafael J. Wysocki type's .online() is executed successfully. 21