Quoting Hans de Goede (2021-02-11 10:36:13) > Hi, > > On 2/10/21 1:48 PM, Chris Wilson wrote: > > Quoting Hans de Goede (2021-02-10 10:37:19) > >> Hi, > >> > >> On 2/10/21 12:07 AM, Chris Wilson wrote: > >>> Quoting Hans de Goede (2021-02-09 11:46:46) > >>>> Hi, > >>>> > >>>> On 2/9/21 12:27 AM, Chris Wilson wrote: > >>>>> Quoting Hans de Goede (2021-02-08 20:38:58) > >>>>>> Hi All, > >>>>>> > >>>>>> We (Fedora) have been receiving reports from multiple users about gfx issues / glitches > >>>>>> stating with 5.10.9. All reporters are users of Ivy Bridge / Haswell iGPUs and all > >>>>>> reporters report that adding i915.mitigations=off to the cmdline fixes things, see: > >>>>> > >>>>> I tried to reproduce this on the w/e on hsw-gt1, to no avail; and piglit > >>>>> did not report any differences with and without mitigations. I have yet > >>>>> to test other platforms. So I don't yet have an alternative. > >>>> > >>>> Note the original / first reporter of: > >>>> > >>>> https://bugzilla.redhat.com/show_bug.cgi?id=1925346 > >>>> > >>>> Is using hsw-gt2, so it seems that the problem is not just the enabling of > >>>> the mitigations on ivy-bridge / bay-trail but that there actually is > >>>> a regression on devices where the WA worked fine before... > >>> > >>> There have been 3 crashes uploaded related to v5.10.9, and in all 3 > >>> cases the ACTHD has been in the first page. This strongly suggests that > >>> the w/a is scribbling over address 0. And there's then a very good > >>> chance that > >>> > >>> commit 29d35b73ead4e41aa0d1a954c9bfbdce659ec5d6 > >>> Author: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > >>> Date: Mon Jan 25 12:50:33 2021 +0000 > >>> > >>> drm/i915/gt: Always try to reserve GGTT address 0x0 > >>> > >>> commit 489140b5ba2e7cc4b853c29e0591895ddb462a82 upstream. > >>> > >>> in v5.10.14 is sufficient to hide the issue. > >> > >> That one actually is already in v5.10.13 and the various reportes of these > >> issues have already tested 5.10.13. They did mention that it took longer > >> to reproduce with 5.10.13 then with 5.10.10, but that could also be due to: > >> > >> "drm/i915/gt: Clear CACHE_MODE prior to clearing residuals" > >> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-5.10.y&id=520d05a77b2866eb4cb9e548e1d8c8abcfe60ec5 > > > > Started looking for scratch page overwrites, and found this little gem: > > https://patchwork.freedesktop.org/patch/420436/?series=86947&rev=1 > > > > Looks promising wrt the cause of overwriting random addresses -- and > > I hope that is the explanation for the glitches/hangs. I have a hsw gt2 > > with gnome shell, piglit is happy, but I suspect it is all due to > > placement and so will only occur at random. > > If you can give me a list of commits to cherry-pick then I can prepare > a Fedora 5.10.y kernel which those added for the group of Fedora users > who are hitting this to test. e627d5923cae ("drm/i915/gt: One more flush for Baytrail clear residuals") d30bbd62b1bf ("drm/i915/gt: Flush before changing register state") 1914911f4aa0 ("drm/i915/gt: Correct surface base address for renderclear") are missing from v5.10.15 -Chris
