Re: [PATCH v2 6/6] drm/nouveau/kms/nv50-: Obliterate nouveau_encoder->crtc

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Encoder atomic disable callback calls a sleeping function, violating atomic context rules.
--

--- Patch [6]: [PATCH v2 6/6] drm/nouveau/kms/nv50-: Obliterate nouveau_encoder->crtc ---
commit 9b6ea3488cdb59d28deb854dd17d63d4b20e1a27
Author: Lyude Paul <lyude@redhat.com>

drm/nouveau/kms/nv50-: Obliterate nouveau_encoder->crtc

This commit removes the nouveau_encoder->crtc tracking artifact from the
pre-atomic modesetting days. It relies entirely on the atomic state to
track the assigned CRTC, as all redundant legacy tracking users have
been removed.

> diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
> --- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
> +++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
[ ... ]
> @@ -1634,7 +1631,6 @@ nv50_sor_atomic_disable(struct drm_encoder *encoder, struct drm_atomic_commit *s
>  
>  	nv_encoder->update(nv_encoder, head->base.index, NULL, 0, 0);
>  	nv50_audio_disable(encoder, &head->base);

[Severity: High]
This is a pre-existing issue, but I noticed a potential sleep-in-atomic bug
in this execution path.

The nv50_sor_atomic_disable() function is an encoder atomic disable callback,
which runs in an atomic context during non-blocking commits. It explicitly
calls nv50_audio_disable():

nv50_sor_atomic_disable()
  nv50_audio_disable(encoder, &head->base);

Looking at nv50_audio_disable(), it acquires a mutex:

nv50_audio_disable()
  mutex_lock(&drm->audio.lock);

Can this cause system instability or kernel warnings by calling a sleeping
function (mutex_lock) from an atomic context?

> -	nv_encoder->crtc = NULL;
>  }

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260819155934.154125-1-lyude@redhat.com?part=6