Re: [PATCH v7 08/13] drm/i915/display: Warn on use_dsb in non-dsb pipe update functions

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Feb 12, 2025 at 09:57:37AM +0200, Jouni Högander wrote:
> Add drm_WARN_ON(use_dsb) into commit_pipe_{pre,post}_planes() and
> intel_pipe_update_{start,end}() as they are not supposed to get called on
> non-dsb updates.
> 
> Signed-off-by: Jouni Högander <jouni.hogander@intel.com>

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_crtc.c    | 4 ++++
>  drivers/gpu/drm/i915/display/intel_display.c | 6 +++++-
>  2 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c
> index 89785da93603..eb089d76ba2a 100644
> --- a/drivers/gpu/drm/i915/display/intel_crtc.c
> +++ b/drivers/gpu/drm/i915/display/intel_crtc.c
> @@ -522,6 +522,8 @@ void intel_pipe_update_start(struct intel_atomic_state *state,
>  	struct intel_vblank_evade_ctx evade;
>  	int scanline;
>  
> +	drm_WARN_ON(display->drm, new_crtc_state->use_dsb);
> +
>  	intel_psr_lock(new_crtc_state);
>  
>  	if (new_crtc_state->do_async_flip) {
> @@ -660,6 +662,8 @@ void intel_pipe_update_end(struct intel_atomic_state *state,
>  	ktime_t end_vbl_time = ktime_get();
>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>  
> +	drm_WARN_ON(display->drm, new_crtc_state->use_dsb);
> +
>  	if (new_crtc_state->do_async_flip)
>  		goto out;
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index cab6852dd9c2..79b8d2ad3b9c 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -7141,11 +7141,13 @@ static void commit_pipe_pre_planes(struct intel_atomic_state *state,
>  		intel_atomic_get_new_crtc_state(state, crtc);
>  	bool modeset = intel_crtc_needs_modeset(new_crtc_state);
>  
> +	drm_WARN_ON(&dev_priv->drm, new_crtc_state->use_dsb);
> +
>  	/*
>  	 * During modesets pipe configuration was programmed as the
>  	 * CRTC was enabled.
>  	 */
> -	if (!modeset && !new_crtc_state->use_dsb) {
> +	if (!modeset) {
>  		if (intel_crtc_needs_color_update(new_crtc_state))
>  			intel_color_commit_arm(NULL, new_crtc_state);
>  
> @@ -7168,6 +7170,8 @@ static void commit_pipe_post_planes(struct intel_atomic_state *state,
>  	const struct intel_crtc_state *new_crtc_state =
>  		intel_atomic_get_new_crtc_state(state, crtc);
>  
> +	drm_WARN_ON(&dev_priv->drm, new_crtc_state->use_dsb);
> +
>  	/*
>  	 * Disable the scaler(s) after the plane(s) so that we don't
>  	 * get a catastrophic underrun even if the two operations
> -- 
> 2.43.0

-- 
Ville Syrjälä
Intel