Re: [Regression] Panel flickering on Dell XPS 13 9360 with drm-fixes-2025-06-28 merged (Linux 6.16-rc4)

[Paul Menzel <pmenzel@molgen.mpg.de>]

Dear Imre,


Thank you for your reply.


Am 30.06.25 um 09:41 schrieb Imre Deak:
> On Sun, Jun 29, 2025 at 11:04:31PM +0200, Paul Menzel wrote:

>> Just a heads-up, that very likely, merging of branch *drm-fixes-2025-06-28*
>> causes flickering of the panel of the Intel Kaby Lake laptop Dell XPS 13
>> 9360. 6.16.0-rc3 works fine, and with 6.16-rc3-00329-gdfba48a70cb6 the panel
>> flickers. I try to bisect, but maybe you already have an idea.
> 
> One possibility is:
> a3ef3c2da675 ("drm/dp: Change AUX DPCD probe address from DPCD_REV to LANE0_1_STATUS")

Yes, that is the one my bisection pinpointed.

> Could you open a ticket for this and provide a drm.debug=0x10e log with
> 6.16-rc4 and try if the following commits in drm-tip fixes the issue?:
> 
> 5281cbe0b55a ("drm/edid: Define the quirks in an enum list")
> 0b4aa85e8981 ("drm/edid: Add support for quirks visible to DRM core and drivers")
> b87ed522b364 ("drm/dp: Add an EDID quirk for the DPCD register access probe")
> ed3648b9ec4c ("drm/i915/dp: Disable the AUX DPCD probe quirk if it's not required")
> 
> I also pushed these to:
> https://github.com/ideak/linux/commits/dpcd-probe-quirk

I created issue *[Regression] Panel flickering on Dell XPS 13 9360 with 
drm-fixes-2025-06-28 merged (Linux 6.16-rc4)* [1], and will try your 
proposed fixes later.

[…]


Kind regards,

Paul


[1]: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14558