Hello Manuel, On Sat, Sep 05, 2026 at 06:44:58PM -0500, Manuel Buffa wrote: > I completed the requested bisection between stable v6.12.101 and v6.12.105 > on the affected machine. > > The kernel configuration was derived on the affected work-box while it was > running Debian 6.12.101 using the requested localmodconfig / savedefconfig > procedure. I froze that my_defconfig and used it for every build. > Compilation and packaging occurred on a separate amd64 builder; every > GOOD/BAD classification came only from the work-box with its RX480/Polaris10 > GPU under real RustDesk H.264 VAAPI use. > > The endpoints reproduced as follows: > > v6.12.101 GOOD > v6.12.105 BAD > > The complete git bisect log is attached. Git mechanically identified: > > 52566c150cadb1a17df840dd25862a61dcf84bed is the first bad commit > drm/amdgpu: check ASPM on the dGPU host link > > Its immediate parent, fa9624ad4d6d4b25e448dbc550ddc69e6f849640, tested GOOD > during the bisection. I subsequently qualified that exact parent in two real > RustDesk H.264 VAAPI sessions totalling about 43 minutes, including a > deliberate disconnect/reconnect. All 288 periodic samples and the complete > kernel journal were free of the characteristic timeout/reset signatures. It > is now the pinned operational kernel on this work-box, and two consecutive > normal boots plus a further 10-minute H.264 VAAPI canary were clean.
Thanks for going through that!
> There is an important causal qualification. I also built a clean v6.12.105
> tree with only 52566c150cad... reverted. That kernel remained BAD: after
> about 79 seconds of real RustDesk H.264 VAAPI activity, the work-box
> reproduced the same sequence:
>
> ring vce0 timeout
> GPU reset begin!
> VRAM is lost due to GPU reset!
:-(. So 52566c150cad wasn't the real (or single) reason for the
regression you see. If I understand correctly the symptoms on
52566c150cad were also slightly different.
Can you please test 5f46322e0b84af29e10eb951ff45bd6ea40640de,
869eb255e499112f9ffb42e7fa96ff2fca0df54b and
81b5af1fb0f14cace6c3b3130a05e5602a597820 with 52566c150cad reverted?
(That is
git checkout 5f46322e0b84af29e10eb951ff45bd6ea40640de,
git revert 52566c150cad
... build and test according to Salvatore's instructions
and the same for the other two commits.)
I think with these results we can report upstream and let the amdgpu
experts work out the rest (or ask smarter questions).
Best regards
Uwe
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