drm/amd/display: revert support for DID2.0 dsc passthrough

3x4K60 displays over MST with DSC enabled was not able to light up
due to this patch.
Signed-off-by: Jun Lei <jun.lei@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dc_dsc.h

@@ -51,7 +51,6 @@ struct dc_dsc_policy {
 	int min_slice_height; // Must not be less than 8
 	uint32_t max_target_bpp;
 	uint32_t min_target_bpp;
-	uint32_t preferred_bpp_x16;
 	bool enable_dsc_when_not_needed;
 };
 
@@ -63,8 +62,8 @@ bool dc_dsc_parse_dsc_dpcd(const struct dc *dc,
 bool dc_dsc_compute_bandwidth_range(
 		const struct display_stream_compressor *dsc,
 		uint32_t dsc_min_slice_height_override,
-		uint32_t min_bpp_x16,
-		uint32_t max_bpp_x16,
+		uint32_t min_bpp,
+		uint32_t max_bpp,
 		const struct dsc_dec_dpcd_caps *dsc_sink_caps,
 		const struct dc_crtc_timing *timing,
 		struct dc_dsc_bw_range *range);
@@ -79,7 +78,7 @@ bool dc_dsc_compute_config(
 		struct dc_dsc_config *dsc_cfg);
 
 void dc_dsc_get_policy_for_timing(const struct dc_crtc_timing *timing,
-		uint32_t max_target_bpp_limit_override_x16,
+		uint32_t max_target_bpp_limit_override,
 		struct dc_dsc_policy *policy);
 
 void dc_dsc_policy_set_max_target_bpp_limit(uint32_t limit);

drivers/gpu/drm/amd/display/dc/dc_hw_types.h

@@ -769,7 +769,6 @@ struct dc_crtc_timing {
 #endif
 
 	struct dc_crtc_timing_flags flags;
-	uint32_t dsc_fixed_bits_per_pixel_x16; /* DSC target bitrate in 1/16 of bpp (e.g. 128 -> 8bpp) */
 	struct dc_dsc_config dsc_cfg;
 };
 

drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c

@@ -369,11 +369,6 @@ static bool decide_dsc_target_bpp_x16(
 		/* enough bandwidth without dsc */
 		*target_bpp_x16 = 0;
 		should_use_dsc = false;
-	} else if (policy->preferred_bpp_x16 > 0 &&
-			policy->preferred_bpp_x16 <= range.max_target_bpp_x16 &&
-			policy->preferred_bpp_x16 >= range.min_target_bpp_x16) {
-		*target_bpp_x16 = policy->preferred_bpp_x16;
-		should_use_dsc = true;
 	} else if (target_bandwidth_kbps >= range.max_kbps) {
 		/* use max target bpp allowed */
 		*target_bpp_x16 = range.max_target_bpp_x16;
@@ -550,7 +545,7 @@ static bool setup_dsc_config(
 		int target_bandwidth_kbps,
 		const struct dc_crtc_timing *timing,
 		int min_slice_height_override,
-		int max_dsc_target_bpp_limit_override_x16,
+		int max_dsc_target_bpp_limit_override,
 		struct dc_dsc_config *dsc_cfg)
 {
 	struct dsc_enc_caps dsc_common_caps;
@@ -569,7 +564,7 @@ static bool setup_dsc_config(
 
 	memset(dsc_cfg, 0, sizeof(struct dc_dsc_config));
 
-	dc_dsc_get_policy_for_timing(timing, max_dsc_target_bpp_limit_override_x16, &policy);
+	dc_dsc_get_policy_for_timing(timing, max_dsc_target_bpp_limit_override, &policy);
 	pic_width = timing->h_addressable + timing->h_border_left + timing->h_border_right;
 	pic_height = timing->v_addressable + timing->v_border_top + timing->v_border_bottom;
 
@@ -870,8 +865,8 @@ bool dc_dsc_parse_dsc_dpcd(const struct dc *dc, const uint8_t *dpcd_dsc_basic_da
 bool dc_dsc_compute_bandwidth_range(
 		const struct display_stream_compressor *dsc,
 		uint32_t dsc_min_slice_height_override,
-		uint32_t min_bpp_x16,
-		uint32_t max_bpp_x16,
+		uint32_t min_bpp,
+		uint32_t max_bpp,
 		const struct dsc_dec_dpcd_caps *dsc_sink_caps,
 		const struct dc_crtc_timing *timing,
 		struct dc_dsc_bw_range *range)
@@ -888,10 +883,10 @@ bool dc_dsc_compute_bandwidth_range(
 
 	if (is_dsc_possible)
 		is_dsc_possible = setup_dsc_config(dsc_sink_caps, &dsc_enc_caps, 0, timing,
-				dsc_min_slice_height_override, max_bpp_x16, &config);
+				dsc_min_slice_height_override, max_bpp, &config);
 
 	if (is_dsc_possible)
-		get_dsc_bandwidth_range(min_bpp_x16, max_bpp_x16, &dsc_common_caps, timing, range);
+		get_dsc_bandwidth_range(min_bpp, max_bpp, &dsc_common_caps, timing, range);
 
 	return is_dsc_possible;
 }
@@ -900,7 +895,7 @@ bool dc_dsc_compute_config(
 		const struct display_stream_compressor *dsc,
 		const struct dsc_dec_dpcd_caps *dsc_sink_caps,
 		uint32_t dsc_min_slice_height_override,
-		uint32_t max_target_bpp_limit_override_x16,
+		uint32_t max_target_bpp_limit_override,
 		uint32_t target_bandwidth_kbps,
 		const struct dc_crtc_timing *timing,
 		struct dc_dsc_config *dsc_cfg)
@@ -913,11 +908,11 @@ bool dc_dsc_compute_config(
 			&dsc_enc_caps,
 			target_bandwidth_kbps,
 			timing, dsc_min_slice_height_override,
-			max_target_bpp_limit_override_x16, dsc_cfg);
+			max_target_bpp_limit_override, dsc_cfg);
 	return is_dsc_possible;
 }
 
-void dc_dsc_get_policy_for_timing(const struct dc_crtc_timing *timing, uint32_t max_target_bpp_limit_override_x16, struct dc_dsc_policy *policy)
+void dc_dsc_get_policy_for_timing(const struct dc_crtc_timing *timing, uint32_t max_target_bpp_limit_override, struct dc_dsc_policy *policy)
 {
 	uint32_t bpc = 0;
 
@@ -972,15 +967,13 @@ void dc_dsc_get_policy_for_timing(const struct dc_crtc_timing *timing, uint32_t
 		return;
 	}
 
-	policy->preferred_bpp_x16 = timing->dsc_fixed_bits_per_pixel_x16;
-
 	/* internal upper limit, default 16 bpp */
 	if (policy->max_target_bpp > dsc_policy_max_target_bpp_limit)
 		policy->max_target_bpp = dsc_policy_max_target_bpp_limit;
 
 	/* apply override */
-	if (max_target_bpp_limit_override_x16 && policy->max_target_bpp > max_target_bpp_limit_override_x16 / 16)
-		policy->max_target_bpp = max_target_bpp_limit_override_x16 / 16;
+	if (max_target_bpp_limit_override && policy->max_target_bpp > max_target_bpp_limit_override)
+		policy->max_target_bpp = max_target_bpp_limit_override;
 
 	/* enable DSC when not needed, default false */
 	if (dsc_policy_enable_dsc_when_not_needed)