Re: [regression] Re: Linux 6.12.75

[Thorsten Leemhuis]

On 4/2/26 10:44, Vitaly Chikunov wrote:
> Sasha,
> 
> 1. I cannot find this commit posted on lore.kernel.org to report to
> exact patch.
> 
> | From: Matt Roper <matthew.d.roper@xxxxxxxxx>
> | Date: Tue, 10 Sep 2024 16:47:29 -0700
> | Subject: [PATCH 6.12/sisyphus] drm/xe: Switch MMIO interface to take xe_mmio
> |  instead of xe_gt
> | 
> | [ Upstream commit a84590c5ceb354d2e9f7f6812cfb3a9709e14afa ]
> | 
> | Since much of the MMIO register access done by the driver is to non-GT
> | registers, use of 'xe_gt' in these interfaces has been a long-standing
> | design flaw that's been hard to disentangle.
> [...]
> 
> 2. After this patch applied to 6.12.75 there is kernel NULL pointer
> dereference BUG on MSI MAG H670 12th Gen Intel(R) Core(TM) i5-12600K
> with ASRock Intel Arc B580 Challenger [Alchemist], 12GB:
> [...]
> The commit is found not by a git bisect (since it's reported by end
> user and I cannot reproduce it on my hardware) but (by analyzing dmesg)
> with:
> [...]
> Then finding the suspecting commit:
> 
>   $ git log --oneline -G'XE_LUNARLAKE' v6.12.74..v6.12.75
>   26a40327c25c drm/xe: Switch MMIO interface to take xe_mmio instead of xe_gt
> 
> 6.18 and above are not affected by the bug. Also, they have another commit
> modifying the line which is not present in 6.12 branch:
> [...]
> Related drm/xe bug report https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/7661
Nobody reacted to this and it seems the gitlab ticket is stalled, too.
So let me ask: can this be resolved by reverting 26a40327c25c in 6.12.y?

Ciao, Thorsten