drm/i915/dp: Use connector DSC DPCD in intel_dp_dsc_compute_max_bpp()

Use the connector's DSC DPCD capabilities in intel_dp_dsc_compute_max_bpp()
instead of the version stored in the encoder.
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231006133727.1822579-7-imre.deak@intel.com

drivers/gpu/drm/i915/display/intel_dp.c

@@ -1215,7 +1215,7 @@ intel_dp_mode_valid(struct drm_connector *_connector,
 		 * TBD pass the connector BPC,
 		 * for now U8_MAX so that max BPC on that platform would be picked
 		 */
-		pipe_bpp = intel_dp_dsc_compute_max_bpp(intel_dp, U8_MAX);
+		pipe_bpp = intel_dp_dsc_compute_max_bpp(connector, U8_MAX);
 
 		/*
 		 * Output bpp is stored in 6.4 format so right shift by 4 to get the
@@ -1577,9 +1577,10 @@ u8 intel_dp_dsc_max_src_input_bpc(struct drm_i915_private *i915)
 	return 0;
 }
 
-int intel_dp_dsc_compute_max_bpp(struct intel_dp *intel_dp, u8 max_req_bpc)
+int intel_dp_dsc_compute_max_bpp(const struct intel_connector *connector,
+				 u8 max_req_bpc)
 {
-	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
+	struct drm_i915_private *i915 = to_i915(connector->base.dev);
 	int i, num_bpc;
 	u8 dsc_bpc[3] = {0};
 	u8 dsc_max_bpc;
@@ -1591,7 +1592,7 @@ int intel_dp_dsc_compute_max_bpp(struct intel_dp *intel_dp, u8 max_req_bpc)
 
 	dsc_max_bpc = min_t(u8, dsc_max_bpc, max_req_bpc);
 
-	num_bpc = drm_dp_dsc_sink_supported_input_bpcs(intel_dp->dsc_dpcd,
+	num_bpc = drm_dp_dsc_sink_supported_input_bpcs(connector->dp.dsc_dpcd,
 						       dsc_bpc);
 	for (i = 0; i < num_bpc; i++) {
 		if (dsc_max_bpc >= dsc_bpc[i])
@@ -2056,6 +2057,8 @@ static int intel_edp_dsc_compute_pipe_bpp(struct intel_dp *intel_dp,
 					  struct link_config_limits *limits)
 {
 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
+	struct intel_connector *connector =
+		to_intel_connector(conn_state->connector);
 	int pipe_bpp, forced_bpp;
 	int dsc_src_min_bpp, dsc_sink_min_bpp, dsc_min_bpp;
 	int dsc_src_max_bpp, dsc_sink_max_bpp, dsc_max_bpp;
@@ -2068,7 +2071,7 @@ static int intel_edp_dsc_compute_pipe_bpp(struct intel_dp *intel_dp,
 		int max_bpc = min(limits->pipe.max_bpp / 3, (int)conn_state->max_requested_bpc);
 
 		/* For eDP use max bpp that can be supported with DSC. */
-		pipe_bpp = intel_dp_dsc_compute_max_bpp(intel_dp, max_bpc);
+		pipe_bpp = intel_dp_dsc_compute_max_bpp(connector, max_bpc);
 		if (!is_dsc_pipe_bpp_sufficient(i915, conn_state, limits, pipe_bpp)) {
 			drm_dbg_kms(&i915->drm,
 				    "Computed BPC is not in DSC BPC limits\n");

drivers/gpu/drm/i915/display/intel_dp.h

@@ -116,7 +116,8 @@ void intel_read_dp_sdp(struct intel_encoder *encoder,
 		       struct intel_crtc_state *crtc_state,
 		       unsigned int type);
 bool intel_digital_port_connected(struct intel_encoder *encoder);
-int intel_dp_dsc_compute_max_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc);
+int intel_dp_dsc_compute_max_bpp(const struct intel_connector *connector,
+				 u8 dsc_max_bpc);
 u16 intel_dp_dsc_get_max_compressed_bpp(struct drm_i915_private *i915,
 					u32 link_clock, u32 lane_count,
 					u32 mode_clock, u32 mode_hdisplay,

drivers/gpu/drm/i915/display/intel_dp_mst.c

@@ -1003,7 +1003,7 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
 		 * TBD pass the connector BPC,
 		 * for now U8_MAX so that max BPC on that platform would be picked
 		 */
-		int pipe_bpp = intel_dp_dsc_compute_max_bpp(intel_dp, U8_MAX);
+		int pipe_bpp = intel_dp_dsc_compute_max_bpp(intel_connector, U8_MAX);
 
 		if (drm_dp_sink_supports_fec(intel_dp->fec_capable)) {
 			dsc_max_compressed_bpp =