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Diffstat (limited to 'Documentation/usb')
| -rw-r--r-- | Documentation/usb/power-management.txt | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/usb/power-management.txt b/Documentation/usb/power-management.txt index 97842deec471..b2fc4d4a9917 100644 --- a/Documentation/usb/power-management.txt +++ b/Documentation/usb/power-management.txt @@ -278,6 +278,14 @@ optional. The methods' jobs are quite simple: (although the interfaces will be in the same altsettings as before the suspend). +If the device is disconnected or powered down while it is suspended, +the disconnect method will be called instead of the resume or +reset_resume method. This is also quite likely to happen when +waking up from hibernation, as many systems do not maintain suspend +current to the USB host controllers during hibernation. (It's +possible to work around the hibernation-forces-disconnect problem by +using the USB Persist facility.) + The reset_resume method is used by the USB Persist facility (see Documentation/usb/persist.txt) and it can also be used under certain circumstances when CONFIG_USB_PERSIST is not enabled. Currently, if a |