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Groups > linux.kernel > #1649453
| From | David Woodhouse <dwmw2@infradead.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2] PCI: Add ATS-disable quirk for AMD Stoney GPUs |
| Date | 2017-05-24 12:50 +0200 |
| Message-ID | <tKC1A-1db-9@gated-at.bofh.it> (permalink) |
| References | <ttDdo-8mD-27@gated-at.bofh.it> <ttFfc-1ms-31@gated-at.bofh.it> <tDmbf-28q-7@gated-at.bofh.it> <tKo8i-7OL-7@gated-at.bofh.it> <tKA9s-8rl-37@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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On Wed, 2017-05-24 at 10:44 +0200, Joerg Roedel wrote: > 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. The above patch doesn't actually fix any spec violation which could the GPU an *excuse* to crash and stop responding to invalidations, does it? It just seems to reduce the invalidation load a little, and thus paper over the problem that the card tends to crash under load. Absent a more coherent explanation, it still seems like the correct answer is to blacklist these devices for ATS because they're broken.
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RE: [PATCH v2] PCI: Add ATS-disable quirk for AMD Stoney GPUs "Deucher, Alexander" <Alexander.Deucher@amd.com> - 2017-05-23 22:00 +0200
Re: [PATCH v2] PCI: Add ATS-disable quirk for AMD Stoney GPUs Joerg Roedel <jroedel@suse.de> - 2017-05-24 10:50 +0200
Re: [PATCH v2] PCI: Add ATS-disable quirk for AMD Stoney GPUs David Woodhouse <dwmw2@infradead.org> - 2017-05-24 12:50 +0200
RE: [PATCH v2] PCI: Add ATS-disable quirk for AMD Stoney GPUs "Deucher, Alexander" <Alexander.Deucher@amd.com> - 2017-05-24 15:10 +0200
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