RE: Some 7.1-post fixes that might be worth picking up rather sooner than later

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> -----Original Message-----
> From: Thorsten Leemhuis <[email protected]>
> Sent: Tuesday, July 7, 2026 6:19 AM
> To: Greg KH <[email protected]>
> Cc: Sasha Levin <[email protected]>; Linux kernel regressions list
> <[email protected]>; [email protected]; Deucher, Alexander
> <[email protected]>; Koenig, Christian
> <[email protected]>; Dave Airlie <[email protected]>; Simona
> Vetter <[email protected]>; Linus Torvalds <[email protected]>
> Subject: Re: Some 7.1-post fixes that might be worth picking up rather sooner
> than later
>
> [CCing a few people]
>
> On 6/22/26 07:32, Greg KH wrote:
> > On Fri, Jun 19, 2026 at 11:43:41AM +0200, Greg KH wrote:
> >> On Fri, Jun 19, 2026 at 08:04:35AM +0200, Thorsten Leemhuis wrote:
> >>> Hi Stable Team! From the regressions point I think it might be nice
> >>> to pick up the following changes for the next round of stable updates (e.g.
> >>> 7.1.2), as they seem to fix regressions I've seen multiple people
> >>> report with 7.1:
> >>> [...]
> >>> * 12f58a6caad3be ("drm/amd/display: Fix Color Manager (3DLUT,
> >>> Shaper,
> >>> Blend)") [v7.1-post]
> >
> > This doesn't apply to 7.1.y, and would need a working backport.
> Just a quick status update twimc:
>
> I pointed that out in
> https://gitlab.freedesktop.org/drm/amd/-/work_items/5396 , but nothing
> happened from the AMD side afaics. They have much on their plate, I fully
> understand that, I guess it fell through the cracks (maybe this mail helps).
> Thing is: the backport of the revert is quite big, so nobody else (including me)
> did yet dare to submit it themselves.

I've put a backport on the ticket.  Just waiting for verification from the affected users.

Alex

>
> So two weeks later the regression caused by e56e3cff2a1bb2
> ("drm/amd/display: Sync dcn42 with DC 3.2.373") [v7.1-rc1] is still unfixed in
> 7.1.y as far as I can see it -- a regression that is known since more than two
> months now, as the revert to fix it (12f58a6caad3be, mentioned in the quote
> above) was submitted already on 2026-04-29, but only made it to mainline
> during the merge window for 7.2 (this is another thing that afaics fell through
> the cracks; sadly I only became aware of the regression after 7.1 was out,
> otherwise I would have made noise earlier to get it included in 7.1).
>
> This all seems rather unfortunate.
>
> Luckily is seems the KDE Plasma developer turned off support for the color
> pipeline stuff in Kwin 6.7.1
> (https://invent.kde.org/plasma/kwin/-
> /commit/9079a417b821f80c0d9e3bc5014a388e0e340f82
> ), which apparently avoids the problem for many users (see the
> gitlab.freedesktop ticket linked earlier).
>
> Ciao, Thorsten