14f3549d7SRafael J. WysockiWhat: /sys/devices/.../online 24f3549d7SRafael J. WysockiDate: April 2013 34f3549d7SRafael J. WysockiContact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 44f3549d7SRafael J. WysockiDescription: 54f3549d7SRafael J. Wysocki The /sys/devices/.../online attribute is only present for 64f3549d7SRafael J. Wysocki devices whose bus types provide .online() and .offline() 74f3549d7SRafael J. Wysocki callbacks. The number read from it (0 or 1) reflects the value 84f3549d7SRafael J. Wysocki of the device's 'offline' field. If that number is 1 and '0' 94f3549d7SRafael J. Wysocki (or 'n', or 'N') is written to this file, the device bus type's 104f3549d7SRafael J. Wysocki .offline() callback is executed for the device and (if 114f3549d7SRafael J. Wysocki successful) its 'offline' field is updated accordingly. In 124f3549d7SRafael J. Wysocki turn, if that number is 0 and '1' (or 'y', or 'Y') is written to 134f3549d7SRafael J. Wysocki this file, the device bus type's .online() callback is executed 144f3549d7SRafael J. Wysocki for the device and (if successful) its 'offline' field is 154f3549d7SRafael J. Wysocki updated as appropriate. 164f3549d7SRafael J. Wysocki 174f3549d7SRafael J. Wysocki After a successful execution of the bus type's .offline() 184f3549d7SRafael J. Wysocki callback the device cannot be used for any purpose until either 194f3549d7SRafael J. Wysocki it is removed (i.e. device_del() is called for it), or its bus 20*ebab9426SBjorn Helgaas type's .online() is executed successfully. 21