Re: [PATCH 4/4] drm/i915/display: Add handling for new "active bpc" property

[Ville Syrjälä]

On Fri, Jun 04, 2021 at 07:17:23PM +0200, Werner Sembach wrote:
> This commits implements the "active bpc" drm property for the Intel GPU driver.
> 
> Signed-off-by: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 13 +++++++++++++
>  drivers/gpu/drm/i915/display/intel_dp.c      |  8 ++++++--
>  drivers/gpu/drm/i915/display/intel_dp_mst.c  |  4 +++-
>  drivers/gpu/drm/i915/display/intel_hdmi.c    |  4 +++-
>  4 files changed, 25 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 64e9107d70f7..f7898d9d7438 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -10164,6 +10164,8 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
>  	struct drm_i915_private *dev_priv = to_i915(dev);
>  	struct intel_crtc_state *new_crtc_state, *old_crtc_state;
>  	struct intel_crtc *crtc;
> +	struct drm_connector *connector;
> +	struct drm_connector_state *new_conn_state;
>  	u64 put_domains[I915_MAX_PIPES] = {};
>  	intel_wakeref_t wakeref = 0;
>  	int i;
> @@ -10324,6 +10326,17 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
>  	}
>  	intel_runtime_pm_put(&dev_priv->runtime_pm, state->wakeref);
>  
> +	/* Extract information from crtc to communicate it to userspace as connector properties */
> +	for_each_new_connector_in_state(&state->base, connector, new_conn_state, i) {
> +		struct drm_crtc *crtc = new_conn_state->crtc;
> +		if (crtc) {
> +			new_crtc_state = to_intel_crtc_state(drm_atomic_get_new_crtc_state(&state->base, crtc));

intel_atomic_get_new_crtc_state()

> +			new_conn_state->active_bpc = new_crtc_state->pipe_bpp / 3;
> +		}
> +		else
> +			new_conn_state->active_bpc = 0;
> +	}

This also seems too late. I think the whole thing should be
done somewhere around the normal swap_state() stuff.

> +
>  	/*
>  	 * Defer the cleanup of the old state to a separate worker to not
>  	 * impede the current task (userspace for blocking modesets) that
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 642c60f3d9b1..67826ba976ed 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4671,10 +4671,14 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
>  		intel_attach_force_audio_property(connector);
>  
>  	intel_attach_broadcast_rgb_property(connector);
> -	if (HAS_GMCH(dev_priv))
> +	if (HAS_GMCH(dev_priv)) {
>  		drm_connector_attach_max_bpc_property(connector, 6, 10);
> -	else if (DISPLAY_VER(dev_priv) >= 5)
> +		drm_connector_attach_active_bpc_property(connector, 6, 10);
> +	}
> +	else if (DISPLAY_VER(dev_priv) >= 5) {
>  		drm_connector_attach_max_bpc_property(connector, 6, 12);
> +		drm_connector_attach_active_bpc_property(connector, 6, 12);
> +	}
>  
>  	/* Register HDMI colorspace for case of lspcon */
>  	if (intel_bios_is_lspcon_present(dev_priv, port)) {
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 2daa3f67791e..5a1869dc2210 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -844,8 +844,10 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
>  	 */
>  	connector->max_bpc_property =
>  		intel_dp->attached_connector->base.max_bpc_property;
> -	if (connector->max_bpc_property)
> +	if (connector->max_bpc_property) {
>  		drm_connector_attach_max_bpc_property(connector, 6, 12);
> +		drm_connector_attach_active_bpc_property(connector, 6, 12);
> +	}
>  
>  	return connector;
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
> index d69f0a6dc26d..8af78b27b6ce 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
> @@ -2463,8 +2463,10 @@ intel_hdmi_add_properties(struct intel_hdmi *intel_hdmi, struct drm_connector *c
>  		drm_object_attach_property(&connector->base,
>  			connector->dev->mode_config.hdr_output_metadata_property, 0);
>  
> -	if (!HAS_GMCH(dev_priv))
> +	if (!HAS_GMCH(dev_priv)) {
>  		drm_connector_attach_max_bpc_property(connector, 8, 12);
> +		drm_connector_attach_active_bpc_property(connector, 8, 12);
> +	}
>  }
>  
>  /*
> -- 
> 2.25.1

-- 
Ville Syrjälä
Intel