Hi Alexander, On Tue, May 23, 2017 at 07:54:12PM +0000, Deucher, Alexander wrote: > I finally got an answer from the hw team and we validated ATS on > stoney as well so in theory this patch shouldn’t actually be needed. > I think we may actually be papering over some other issue. The > following patch seems to also fix this issue (and other issues): > https://www.spinics.net/lists/stable/msg172631.html Yeah, but it still looks to me like that the hardware got into some weird state with the storm of ATS invalidations sent to it. The Completion-Wait loop timeouts seen in the original bug report indicate that the IOMMU is waiting for a response that never comes. And this is probably the ATS flush completion response from the GPU, as disabling ATS on the GPU makes the issue disappear. Regards, Joerg
