On Fri, Jul 24, 2015 at 04:26:27PM +0300, Ander Conselvan De Oliveira wrote: > On Tue, 2015-07-21 at 16:09 +0200, Maarten Lankhorst wrote: > > -EDEADLK has special meaning in atomic, but get_fence may call > > i915_find_fence_reg which can return -EDEADLK. > > > > This has special meaning in the atomic world, so convert the error > > to -EBUSY for this case. > > Doesn't this change the behavior of intel_crtc_page_flip() slightly? It > now would return -EBUSY to user space if it can't find a fence instead > of -EDEADLK. Not sure if that is a problem though. I don't expect user > space would actually check for -EDEADLK.
It's extreme, but we could fix the -EDEADLK by dropping the struct_mutex and flushing the unpin workqueue (there is no other conceivable way of triggering EDEADLK here other than uncompleted flips except for a kernel bug ofc). I can confidently state that no one has or ever will see an EDEADLK here - and even if it did userspace is best to treat it exactly the same as any other error path, cancel the flip and try again later. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
