Re: [PATCH v2 5/6] drm/msm: force mode_changed on color_mgmt_changed, not just ctm

[Val Packett <val@packett.cool>]

On 10/26/26 5:25 PM, Xi Zhang wrote:
> dpu_crtc_atomic_check calls dpu_crtc_assign_resources when
> color_mgmt_changed is set, which is unsafe outside of full modeset.
>
> Set allow_modeset and mode_changed when color_mgmt_changed is set,
> not just when ctm is changed.
>
> Also would fix
> commit 42f62cd79578 ("drm/msm/dpu: try reserving the DSPP-less LM first")
> which was reverted.
>
> Closes: https://gitlab.freedesktop.org/drm/msm/-/work_items/102
>
> Signed-off-by: Xi Zhang <xz.ca.cn@gmail.com>
> ---
>   drivers/gpu/drm/msm/msm_atomic.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
> index a8babf1dbe0d..6f0f30b0728a 100644
> --- a/drivers/gpu/drm/msm/msm_atomic.c
> +++ b/drivers/gpu/drm/msm/msm_atomic.c
> @@ -195,8 +195,7 @@ int msm_atomic_check(struct drm_device *dev, struct drm_atomic_commit *state)
>   	 */
>   	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state,
>   				      new_crtc_state, i) {
> -		if ((old_crtc_state->ctm && !new_crtc_state->ctm) ||
> -		    (!old_crtc_state->ctm && new_crtc_state->ctm)) {
> +		if (new_crtc_state->color_mgmt_changed) {
>   			new_crtc_state->mode_changed = true;
>   			state->allow_modeset = true;
>   		}

This is also handled by patch 9 "drm/msm/dpu: only reassign resources 
when the encoder is reprogrammed" of the smmu fault series:

https://lore.kernel.org/all/20261024-fd-kms-fix-smmu-v5-9-a5b0b284aead@oss.qualcomm.com/


Thanks,
~val