drm/i915/xelpd: Support DP1.4 compression BPPs

Support compression BPPs from bpc to uncompressed BPP -1.
So far we have 8,10,12 as valid compressed BPPS now the
support is extended.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210514153711.2359617-5-matthew.d.roper@intel.com

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

@@ -109,6 +109,7 @@ bool intel_dp_is_edp(struct intel_dp *intel_dp)
 }
 
 static void intel_dp_unset_edid(struct intel_dp *intel_dp);
+static int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc);
 
 /* update sink rates from dpcd */
 static void intel_dp_set_sink_rates(struct intel_dp *intel_dp)
@@ -494,7 +495,8 @@ small_joiner_ram_size_bits(struct drm_i915_private *i915)
 static u16 intel_dp_dsc_get_output_bpp(struct drm_i915_private *i915,
 				       u32 link_clock, u32 lane_count,
 				       u32 mode_clock, u32 mode_hdisplay,
-				       bool bigjoiner)
+				       bool bigjoiner,
+				       u32 pipe_bpp)
 {
 	u32 bits_per_pixel, max_bpp_small_joiner_ram;
 	int i;
@@ -541,12 +543,17 @@ static u16 intel_dp_dsc_get_output_bpp(struct drm_i915_private *i915,
 		return 0;
 	}
 
-	/* Find the nearest match in the array of known BPPs from VESA */
-	for (i = 0; i < ARRAY_SIZE(valid_dsc_bpp) - 1; i++) {
-		if (bits_per_pixel < valid_dsc_bpp[i + 1])
-			break;
+	/* From XE_LPD onwards we support from bpc upto uncompressed bpp-1 BPPs */
+	if (DISPLAY_VER(i915) >= 13) {
+		bits_per_pixel = min(bits_per_pixel, pipe_bpp - 1);
+	} else {
+		/* Find the nearest match in the array of known BPPs from VESA */
+		for (i = 0; i < ARRAY_SIZE(valid_dsc_bpp) - 1; i++) {
+			if (bits_per_pixel < valid_dsc_bpp[i + 1])
+				break;
+		}
+		bits_per_pixel = valid_dsc_bpp[i];
 	}
-	bits_per_pixel = valid_dsc_bpp[i];
 
 	/*
 	 * Compressed BPP in U6.4 format so multiply by 16, for Gen 11,
@@ -780,6 +787,12 @@ intel_dp_mode_valid(struct drm_connector *connector,
 	 */
 	if (DISPLAY_VER(dev_priv) >= 10 &&
 	    drm_dp_sink_supports_dsc(intel_dp->dsc_dpcd)) {
+		/*
+		 * 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_bpp(intel_dp, U8_MAX);
+
 		if (intel_dp_is_edp(intel_dp)) {
 			dsc_max_output_bpp =
 				drm_edp_dsc_sink_output_bpp(intel_dp->dsc_dpcd) >> 4;
@@ -793,7 +806,8 @@ intel_dp_mode_valid(struct drm_connector *connector,
 							    max_lanes,
 							    target_clock,
 							    mode->hdisplay,
-							    bigjoiner) >> 4;
+							    bigjoiner,
+							    pipe_bpp) >> 4;
 			dsc_slice_count =
 				intel_dp_dsc_get_slice_count(intel_dp,
 							     target_clock,
@@ -1240,7 +1254,8 @@ static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
 						    pipe_config->lane_count,
 						    adjusted_mode->crtc_clock,
 						    adjusted_mode->crtc_hdisplay,
-						    pipe_config->bigjoiner);
+						    pipe_config->bigjoiner,
+						    pipe_bpp);
 		dsc_dp_slice_count =
 			intel_dp_dsc_get_slice_count(intel_dp,
 						     adjusted_mode->crtc_clock,