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...
If you have access to a hsw-gt2 device then testing there might help?
Also note that this reproduces more easily on 5.10.10, which does not have:
520d05a77b2866eb ("drm/i915/gt: Clear CACHE_MODE prior to clearing residuals")
Not sure if that helps though.
Though note that v5.11 and v5.12 will behave similarly, so we need to urgently find a fix for Linus's tree anyway.
Ack.
Regards,
Hans