Quoting Chris Wilson (2018-05-22 15:35:34) > In order to prepare the GPU for sleeping, we may want to submit commands > to it. This is a complicated process that may even require some swapping > in from shmemfs, if the GPU was in the wrong state. As such, we need to > do this preparation step synchronously before the rest of the system has > started to turn off (e.g. swapin fails if scsi is suspended). > Fortunately, we are provided with a such a hook, pm_ops.prepare().
Now, this problem would also be solved by RFC drm/i915: Switch to kernel context before idling at runtime as with that patch, we would be sure to already be on the kernel context before we unpin the state and so not need to issue the request to switch. But I think there is a wider problem this solves for us by making sure the backing store is still accessible while we finish off user operations. Otherwise with the async suspend, it does seem like we might find ourselves unable to flush buffers to disk. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
