1 files changed, 50 insertions, 32 deletions

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
index 941e96f100f4..35733d5c5193 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -791,25 +791,12 @@ struct dsc_mst_fairness_params {
 	struct amdgpu_dm_connector *aconnector;
 };
 
-static uint16_t get_fec_overhead_multiplier(struct dc_link *dc_link)
-{
-	u8 link_coding_cap;
-	uint16_t fec_overhead_multiplier_x1000 = PBN_FEC_OVERHEAD_MULTIPLIER_8B_10B;
-
-	link_coding_cap = dc_link_dp_mst_decide_link_encoding_format(dc_link);
-	if (link_coding_cap == DP_128b_132b_ENCODING)
-		fec_overhead_multiplier_x1000 = PBN_FEC_OVERHEAD_MULTIPLIER_128B_132B;
-
-	return fec_overhead_multiplier_x1000;
-}
-
-static int kbps_to_peak_pbn(int kbps, uint16_t fec_overhead_multiplier_x1000)
+static int kbps_to_peak_pbn(int kbps)
 {
 	u64 peak_kbps = kbps;
 
 	peak_kbps *= 1006;
-	peak_kbps *= fec_overhead_multiplier_x1000;
-	peak_kbps = div_u64(peak_kbps, 1000 * 1000);
+	peak_kbps = div_u64(peak_kbps, 1000);
 	return (int) DIV64_U64_ROUND_UP(peak_kbps * 64, (54 * 8 * 1000));
 }
 
@@ -910,12 +897,11 @@ static int increase_dsc_bpp(struct drm_atomic_state *state,
 	int link_timeslots_used;
 	int fair_pbn_alloc;
 	int ret = 0;
-	uint16_t fec_overhead_multiplier_x1000 = get_fec_overhead_multiplier(dc_link);
 
 	for (i = 0; i < count; i++) {
 		if (vars[i + k].dsc_enabled) {
 			initial_slack[i] =
-			kbps_to_peak_pbn(params[i].bw_range.max_kbps, fec_overhead_multiplier_x1000) - vars[i + k].pbn;
+			kbps_to_peak_pbn(params[i].bw_range.max_kbps) - vars[i + k].pbn;
 			bpp_increased[i] = false;
 			remaining_to_increase += 1;
 		} else {
@@ -1011,7 +997,6 @@ static int try_disable_dsc(struct drm_atomic_state *state,
 	int next_index;
 	int remaining_to_try = 0;
 	int ret;
-	uint16_t fec_overhead_multiplier_x1000 = get_fec_overhead_multiplier(dc_link);
 
 	for (i = 0; i < count; i++) {
 		if (vars[i + k].dsc_enabled
@@ -1041,7 +1026,7 @@ static int try_disable_dsc(struct drm_atomic_state *state,
 		if (next_index == -1)
 			break;
 
-		vars[next_index].pbn = kbps_to_peak_pbn(params[next_index].bw_range.stream_kbps, fec_overhead_multiplier_x1000);
+		vars[next_index].pbn = kbps_to_peak_pbn(params[next_index].bw_range.stream_kbps);
 		ret = drm_dp_atomic_find_time_slots(state,
 						    params[next_index].port->mgr,
 						    params[next_index].port,
@@ -1054,7 +1039,8 @@ static int try_disable_dsc(struct drm_atomic_state *state,
 			vars[next_index].dsc_enabled = false;
 			vars[next_index].bpp_x16 = 0;
 		} else {
-			vars[next_index].pbn = kbps_to_peak_pbn(params[next_index].bw_range.max_kbps, fec_overhead_multiplier_x1000);
+			vars[next_index].pbn = kbps_to_peak_pbn(
+				params[next_index].bw_range.max_kbps);
 			ret = drm_dp_atomic_find_time_slots(state,
 							    params[next_index].port->mgr,
 							    params[next_index].port,
@@ -1083,7 +1069,6 @@ static int compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
 	int count = 0;
 	int i, k, ret;
 	bool debugfs_overwrite = false;
-	uint16_t fec_overhead_multiplier_x1000 = get_fec_overhead_multiplier(dc_link);
 
 	memset(params, 0, sizeof(params));
 
@@ -1148,7 +1133,7 @@ static int compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
 	/* Try no compression */
 	for (i = 0; i < count; i++) {
 		vars[i + k].aconnector = params[i].aconnector;
-		vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.stream_kbps, fec_overhead_multiplier_x1000);
+		vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.stream_kbps);
 		vars[i + k].dsc_enabled = false;
 		vars[i + k].bpp_x16 = 0;
 		ret = drm_dp_atomic_find_time_slots(state, params[i].port->mgr, params[i].port,
@@ -1167,7 +1152,7 @@ static int compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
 	/* Try max compression */
 	for (i = 0; i < count; i++) {
 		if (params[i].compression_possible && params[i].clock_force_enable != DSC_CLK_FORCE_DISABLE) {
-			vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.min_kbps, fec_overhead_multiplier_x1000);
+			vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.min_kbps);
 			vars[i + k].dsc_enabled = true;
 			vars[i + k].bpp_x16 = params[i].bw_range.min_target_bpp_x16;
 			ret = drm_dp_atomic_find_time_slots(state, params[i].port->mgr,
@@ -1175,7 +1160,7 @@ static int compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
 			if (ret < 0)
 				return ret;
 		} else {
-			vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.stream_kbps, fec_overhead_multiplier_x1000);
+			vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.stream_kbps);
 			vars[i + k].dsc_enabled = false;
 			vars[i + k].bpp_x16 = 0;
 			ret = drm_dp_atomic_find_time_slots(state, params[i].port->mgr,
@@ -1219,8 +1204,10 @@ static bool is_dsc_need_re_compute(
 	if (dc_link->type != dc_connection_mst_branch)
 		return false;
 
-	if (!(dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_SUPPORT ||
-		dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_PASSTHROUGH_SUPPORT))
+	/* add a check for older MST DSC with no virtual DPCDs */
+	if (needs_dsc_aux_workaround(dc_link)  &&
+		(!(dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_SUPPORT ||
+		dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_PASSTHROUGH_SUPPORT)))
 		return false;
 
 	for (i = 0; i < MAX_PIPES; i++)
@@ -1240,7 +1227,15 @@ static bool is_dsc_need_re_compute(
 			continue;
 
 		aconnector = (struct amdgpu_dm_connector *) stream->dm_stream_context;
-		if (!aconnector)
+		if (!aconnector || !aconnector->dsc_aux)
+			continue;
+
+		/*
+		 *	check if cached virtual MST DSC caps are available and DSC is supported
+		 *	as per specifications in their Virtual DPCD registers.
+		*/
+		if (!(aconnector->dc_sink->dsc_caps.dsc_dec_caps.is_dsc_supported ||
+			aconnector->dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_PASSTHROUGH_SUPPORT))
 			continue;
 
 		stream_on_link[new_stream_on_link_num] = aconnector;
@@ -1601,7 +1596,7 @@ enum dc_status dm_dp_mst_is_port_support_mode(
 	struct amdgpu_dm_connector *aconnector,
 	struct dc_stream_state *stream)
 {
-	int bpp, pbn, branch_max_throughput_mps = 0;
+	int pbn, branch_max_throughput_mps = 0;
 	struct dc_link_settings cur_link_settings;
 	unsigned int end_to_end_bw_in_kbps = 0;
 	unsigned int upper_link_bw_in_kbps = 0, down_link_bw_in_kbps = 0;
@@ -1651,11 +1646,34 @@ enum dc_status dm_dp_mst_is_port_support_mode(
 			}
 		}
 	} else {
-		/* check if mode could be supported within full_pbn */
-		bpp = convert_dc_color_depth_into_bpc(stream->timing.display_color_depth) * 3;
-		pbn = drm_dp_calc_pbn_mode(stream->timing.pix_clk_100hz / 10, bpp << 4);
-		if (pbn > aconnector->mst_output_port->full_pbn)
+		/* Check if mode could be supported within max slot
+		 * number of current mst link and full_pbn of mst links.
+		 */
+		int pbn_div, slot_num, max_slot_num;
+		enum dc_link_encoding_format link_encoding;
+		uint32_t stream_kbps =
+			dc_bandwidth_in_kbps_from_timing(&stream->timing,
+				dc_link_get_highest_encoding_format(stream->link));
+
+		pbn = kbps_to_peak_pbn(stream_kbps);
+		pbn_div = dm_mst_get_pbn_divider(stream->link);
+		slot_num = DIV_ROUND_UP(pbn, pbn_div);
+
+		link_encoding = dc_link_get_highest_encoding_format(stream->link);
+		if (link_encoding == DC_LINK_ENCODING_DP_8b_10b)
+			max_slot_num = 63;
+		else if (link_encoding == DC_LINK_ENCODING_DP_128b_132b)
+			max_slot_num = 64;
+		else {
+			DRM_DEBUG_DRIVER("Invalid link encoding format\n");
 			return DC_FAIL_BANDWIDTH_VALIDATE;
+		}
+
+		if (slot_num > max_slot_num ||
+			pbn > aconnector->mst_output_port->full_pbn) {
+			DRM_DEBUG_DRIVER("Mode can not be supported within mst links!");
+			return DC_FAIL_BANDWIDTH_VALIDATE;
+		}
 	}
 
 	/* check is mst dsc output bandwidth branch_overall_throughput_0_mps */