[Intel-gfx] [5.10.y regression] i915 clear-residuals mitigation is causing gfx issues

[Hans de Goede]

Hi,

On 2/14/21 5:00 PM, Hans de Goede wrote:
> Hi,
> 
> On 2/11/21 1:26 PM, Hans de Goede wrote:
>> Hi,
>>
>> On 2/11/21 11:49 AM, Chris Wilson wrote:

<snip>

>>>>> 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")
>>
>> Thanks, the test-kernel is building now. I will let you know when I have
>> heard back from the Fedora users (this will likely take 1-2 days).
> 
> I've heard back from 2 of the reporters who were seeing issues with 5.10.9+
> 
> And I'm happy to report 5.10.15 + the 3 commits mentioned above cherry-picked
> on top fixes the graphics glitches for them.
> 
> So if we can get these 3 commits into 5.10.y and 5.11.y then this should be
> resolved.

Unfortunately I just got a report that 5.10.15 + the 3 extra fixes mentioned
above is still causing issues for one user with a
"thinkpad x230 with i5-3320M (HD Graphics 4000)"

The user descibes the problem as: "still have some minor black squares popping
up while scrolling on Firefox."

I've asked this user to test 5.10.14 + the 3 reverts mentioned earlier in the
thread and that kernel does not have this issue.

Chris, any ideas / more fixes to cherry pick for testing ?

Regards,

Hans