Re: [PATCH v8 22/29] drm/msm/dp: wire MST helpers into atomic check and commit paths

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Medium] drm/msm: link failure from unconditional DP MST calls when
  DRM_MSM_DP=n
--

commit aae2fe1d03e1fee18f3ec2335e15f03b9cd4b21b
Author: Yongxing Mou <yongxing.mou@oss.qualcomm.com>

drm/msm/dp: wire MST helpers into atomic check and commit paths

This commit wires the DisplayPort MST atomic helpers into msm_atomic_check(),
msm_atomic_commit_tail(), and a new msm_atomic_commit_setup() callback.

> diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
> index a8babf1dbe0d3..e70e5088cfe53 100644
> --- a/drivers/gpu/drm/msm/msm_atomic.c
> +++ b/drivers/gpu/drm/msm/msm_atomic.c
> @@ -4,6 +4,7 @@
>   * Author: Rob Clark <robdclark@gmail.com>
>   */
>  
> +#include <drm/display/drm_dp_mst_helper.h>
>  #include <drm/drm_atomic_uapi.h>
>  #include <drm/drm_vblank.h>
>  
> @@ -207,7 +208,11 @@ int msm_atomic_check(struct drm_device *dev, struct drm_atomic_commit *state)
>  	if (ret)
>  		return ret;
>  
> -	return drm_atomic_helper_check(dev, state);
> +	ret = drm_atomic_helper_check(dev, state);
> +	if (ret)
> +		return ret;
> +
> +	return drm_dp_mst_atomic_check(state);
>  }
>  
>  void msm_atomic_commit_tail(struct drm_atomic_commit *state)
> @@ -221,6 +226,8 @@ void msm_atomic_commit_tail(struct drm_atomic_commit *state)
>  
>  	trace_msm_atomic_commit_tail_start(async, crtc_mask);
>  
> +	drm_dp_mst_atomic_wait_for_dependencies(state);
> +
>  	kms->funcs->enable_commit(kms);
>  
>  	/*
> @@ -322,3 +329,8 @@ void msm_atomic_commit_tail(struct drm_atomic_commit *state)
>  
>  	trace_msm_atomic_commit_tail_finish(async, crtc_mask);
>  }
> +
> +int msm_atomic_commit_setup(struct drm_atomic_commit *state)
> +{
> +	return drm_dp_mst_atomic_setup_commit(state);
> +}

[Severity: Medium]
Does this fail to link when CONFIG_DRM_MSM_KMS is enabled and
CONFIG_DRM_MSM_DP is disabled?

msm_atomic.o is built under CONFIG_DRM_MSM_KMS, which only selects
DRM_DISPLAY_HELPER, whereas drm_dp_mst_topology.o is built under
CONFIG_DRM_DISPLAY_DP_HELPER (selected by DRM_MSM_DP) and
drm_dp_mst_helper.h provides no inline stubs for these helpers.  When no
other enabled driver selects DRM_DISPLAY_DP_HELPER, the build fails with
undefined references to drm_dp_mst_atomic_check(),
drm_dp_mst_atomic_wait_for_dependencies(), and
drm_dp_mst_atomic_setup_commit().

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261110-msm-dp-mst-v8-0-d040fb33db5f@oss.qualcomm.com?part=22