PM: Allow USB devices to suspend/resume asynchronously
Set power.async_suspend for USB devices, endpoints and interfaces,
allowing them to be suspended and resumed asynchronously during
system sleep transitions.
The power.async_suspend flag is also set for devices that don't have
suspend or resume callbacks, because otherwise they would make the
main suspend/resume thread wait for their "asynchronous" children
(during suspend) or parents (during resume), effectively negating the
possible gains from executing these devices' suspend and resume
callbacks asynchronously.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 35cc8b9..20ecb4c 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1817,6 +1817,7 @@
/* Tell the world! */
announce_device(udev);
+ device_enable_async_suspend(&udev->dev);
/* Register the device. The device driver is responsible
* for configuring the device and invoking the add-device
* notifier chain (used by usbfs and possibly others).