On Thu, 16 Sep 2010, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rjw@xxxxxxx> > Subject: PM: Fix potential issue with failing asynchronous suspend > > There is a potential issue with the asynchronous suspend code that > a device driver suspending asynchronously may not notice that it > should back off. There are two failing scenarions, (1) when the > driver is waiting for a driver suspending synchronously to complete > and that second driver returns error code, in which case async_error > won't be set and the waiting driver will continue suspending and (2) > after the driver has called device_pm_wait_for_dev() and the waited > for driver returns error code, in which case the caller of > device_pm_wait_for_dev() will not know that there was an error and > will continue suspending. > > To fix this issue make __device_suspend() set async_error, so > async_suspend() doesn't need to set it any more, and make > device_pm_wait_for_dev() return async_error, so that its callers > can check whether or not they should continue suspending. > > No more changes are necessary, since device_pm_wait_for_dev() is > not used by any drivers' suspend routines at the moment. You just squeaked by, since it is _is_ being used by a USB _resume_ routine. :-) Alan Stern _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
