commit 15512021eb3975a8c2366e3883337e252bb0eee5 causes white spots in console screens

[François Valenduc]

Le 14/04/22 à 10:03, Lisovskiy, Stanislav a écrit :
> On Thu, Apr 14, 2022 at 08:33:35AM +0200, François Valenduc wrote:
>> Le 14/04/22 à 08:31, Lisovskiy, Stanislav a écrit :
>>> On Wed, Apr 13, 2022 at 08:12:20PM +0300, Jani Nikula wrote:
>>>> On Wed, 13 Apr 2022, François Valenduc <francoisvalenduc at gmail.com> wrote:
>>>>> Commit 15512021eb3975a8c2366e3883337e252bb0eee5
>>>>> (15512021eb3975a8c2366e3883337e252bb0eee5) causes a lof of white spots
>>>>> to appears on the right upper corner of all console screens (see
>>>>> https://drive.google.com/file/d/13GabEvOIKSAj5yox6ybAZEDu3Ixncw5Q/view).
>>>>> git-bisect shows that this is the offending commit and if I revert it,
>>>>> the problem goes away. The problem still occurs with kernel 5.18-rc2 and
>>>>> to all stable trees where it was applied.
>>>>> Can somebody explains what happens ?
>>>>>
>>>>> The video card is the following: VGA compatible controller: Intel
>>>>> Corporation WhiskeyLake-U GT2 [UHD Graphics 620] (rev 02) (prog-if 00
>>>>> [VGA controller])
>>>>>
>>>>> Please tell me if you need more info.
>>>> That's commit 15512021eb39 ("drm/i915: Workaround broken BIOS DBUF
>>>> configuration on TGL/RKL"), adding Cc's.
>>>>
>>>> Please file a report at fdo gitlab [1] and attach dmesg etc. there.
>>> That commit looks like it is just disabling all the planes, if wrong
>>> dbuf/wm configuration is detected.
>>> However it should do that only once during boot as I understand.
>>>
>>> Are you sure that is exactly this commit which is causing this?
>>> Does the issue appear always?
>>>
>>> Ville Syrjälä, thoughts?
>>>
>>> Stan
>>>
>>>> Thanks,
>>>> Jani.
>>>>
>>>>
>>>> [1] https://gitlab.freedesktop.org/drm/intel/wikis/How-to-file-i915-bugs
>>>>
>>>>
>>>> -- 
>>>> Jani Nikula, Intel Open Source Graphics Center
>> As I said, git-bisect shows it's the offending commit and if I revert it,
>> the problem doesn't happens. Otherwise, it always occurs.
>>
>> François
>>
> Does it just happen all the time or some steps/certain circumstances needed
> for it to happen?
>
> Only suspicion after looking briefly is that once suspend/resume is done
> it might be messing something up. Just a quick guess..
>
> Stan

It occurs permantently as soon as I boot my computer.