On Thu, Feb 25, 2021 at 12:52 PM Hans de Goede
<hdegoede(a)redhat.com> wrote:
>
> Hi,
>
> On 2/25/21 3:37 PM, Justin Forbes wrote:
>> On Thu, Feb 25, 2021 at 7:31 AM Hans de Goede <hdegoede(a)redhat.com> wrote:
>>>
>>> Hi,
>>>
>>> On 2/25/21 1:33 PM, Justin Forbes wrote:
>>>> On Thu, Feb 25, 2021 at 5:44 AM Hans de Goede <hdegoede(a)redhat.com>
wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> On 2/23/21 6:25 PM, Hans de Goede wrote:
>>>>>> Hi,
>>>>>>
>>>>>> I've been working with various reporters to try and get the
sometimes severe
>>>>>> gfx glitches which people are seeing with kernel >= 5.10.9
resolved, see the
>>>>>> following bugs:
>>>>>>
>>>>>> 1843274 - i915 GPU Hang with kernel 5.7 on Haswell (Acer C720P
Chromebook)
>>>>>> 1925346 - Screen glitches after updating to Kernel 5.10.10
>>>>>> 1925903 - Flickering UI elements, screen instability
(Wayland)
>>>>>> 1931065 - Frequent i915 hangs
>>>>>>
>>>>>> I've written 2 patches 2 address this and asked users to test
Fedora-kernel
>>>>>> scratch-builds with those patches added.
>>>>>>
>>>>>> The first patch is i915-revert.patch, this reverts 3 troublesome
commits
>>>>>> which were first added in 5.10.9 these commit change the i915
mitigations
>>>>>> for a year old i915 CVE which IIRC was mostly about data leaking
from a
>>>>>> previous GPU context to the next. These patches enable these
mitigations
>>>>>> on more GPU models, where they were previously disabled because
they were
>>>>>> causing issues...
>>>>>>
>>>>>> Reporters have reported a 100% success-rate in getting rid of the
gfx
>>>>>> issues with these 3 reverts.
>>>>>>
>>>>>> The second patch is i915-fixes.patch, this cherry-picks 3 patches
from
>>>>>> -next instead (these were suggested by i915 upstream) and this
also helps
>>>>>> for most users, but some users still report some rendering
artifacts
>>>>>> (but overall things are much better).
>>>>>>
>>>>>> Upstream has gone silent on the issue of there still being
rendering
>>>>>> artifacts with the 3 cherry-picked fixes unfortunately.
>>>>>>
>>>>>> Given that we are getting more and more bug-reports about this I
think
>>>>>> that we should be do something about this downstream. Upstream
seams
>>>>>> to be aiming for fixing things, rather then reverting, so going
with
>>>>>> i915-fixes.patch will stay the closest to what I expect to land
in
>>>>>> 5.10.y and 5.11.y at some point.
>>>>>
>>>>> The bug reports for this keep coming in; and it seems that this is
>>>>> fully resolved for all reporters except one by the i915-fixes.patch
which
>>>>> I attached earlier; and for the one reporter who is still seeing
some
>>>>> rendering glitches things are much improved, so I think he is also
>>>>> hitting a different issue.
>>>>>
>>>>> Here is the full lists of bugs which I'm aware of which all have
this
>>>>> as root cause:
>>>>>
>>>>> 1843274 - i915 GPU Hang with kernel 5.7 on Haswell (Acer C720P
Chromebook)
>>>>> 1922511 - Recent upgrades caused smearing/tearing
>>>>> 1925346 - Screen glitches after updating to Kernel 5.10.10
>>>>> 1925903 - Flickering UI elements, screen instability (Wayland)
>>>>> 1931065 - Frequent i915 hangs
>>>>>
https://gitlab.freedesktop.org/drm/intel/-/issues/3099
>>>>>
>>>>> So unless there are any objections I would really like to move
forward
>>>>> with adding i915-fixes.patch to the Fedora 5.10.y kernels.
>>>>>
>>>> The actual patch was not attached,
>>>
>>> It was attached to the first email in this thread, I've also attached it
>>> to this email again.
>>
>> Something must have happened, it didn't make my inbox or the list
>> archives. Thanks for the reattach.
>>
>>>> so I could not add it, you are
>>>> welcome to do so, or attach the patch and I will do it.
>>>
>>> If you can take care of this, then that would be great, thanks.
>>
>> This is added and should make 5.10.19 (likely this weekend). Does this
>> need to go into 5.11.y as is, or does something need to change there?
>
> It should apply cleanly to 5.11 too, as that has the same set of
> i915 mitigation fixes/changes which landed 5.10.9+ .
>
> Although since for 5.11 you are using a full linux git tree as base
> it might be cleaner to just cherry pick the 3 commits. Although this will
> require adding drm-intel as
remote:https://cgit.freedesktop.org/drm-intel/
>
> The 3 commits are:
>
> 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")
>
> If you have any issues with applying this to 5.11, please let me know and
> I'll take a look.
>
Thanks, these are applied and will be in 5.11.2