[PATCH v4 5/5] drm/qxl: properly free qxl releases

[Gerd Hoffmann]

> > +	/*
> > +	 * Ask host to release resources (+fill release ring),
> > +	 * then wait for the release actually happening.
> > +	 */
> > +	qxl_io_notify_oom(qdev);
> > +	for (try = 0; try < 20 && atomic_read(&qdev->release_count) > 0; try++)
> > +		msleep(20);
> 
> A bit icky, why not use a wait queue or something like that instead of
> hand-rolling this? Not for perf reasons, just so it's a bit clear who
> waits for whom and why.

There isn't one ready for use, and adding a new one (to wait for the
garbage collection having released something) just for a clean shutdown
looked a bit like overkill.

But after digging a bit more and looking at the qxl_fence_wait() mess I
think adding a wait queue looks like a good idea ...

v5 coming soon ...

take care,
  Gerd