30dbf0c07f
Owain Ainsworth reported an issue between the interaction of the hangcheck and userspace immediately (and permanently) falling back to s/w rasterisation. In order to break the mutex and begin resetting the GPU, we must abort the current operation (usually within the wait) and climb sufficiently far back up the call chain to drop the mutex. In his implementation, Owain has a loop within the ioctl handler to detect the hang and then sleep until the error handler has run. I've chosen to return to userspace and report an EAGAIN which should trigger the userspace ioctl handler to repeat the call (simply because it felt less invasive...). Before hitting a wedged GPU, we then wait upon completion of the error handler. Reported-by: Owain G. Ainsworth <zerooa@googlemail.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>