On Thursday, September 16, 2010, Alan Stern wrote: > 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. :-) I know that, but resume actually doesn't need to care about async_error. Thanks, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
