drm/amd/display: add mst port output bw check

[Why]
when connect one 4k@144hz dp to dsc mst hub, 4k@144hz mode is in valid
mode list. but some mst hub port output bandwidth does not support
4k@144hz.

[How]
add mst port output bandwidth checks, include full_pbn, branch max
throughput mps.
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Jerry Zuo <Jerry.Zuo@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: hersen wu <hersenxs.wu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -7260,7 +7260,11 @@ create_validate_stream_for_sink(struct amdgpu_dm_connector *aconnector,
 			break;
 		}
 
-		dc_result = dc_validate_stream(adev->dm.dc, stream);
+		if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST)
+			dc_result = dm_dp_mst_is_port_support_mode(aconnector, stream);
+
+		if (dc_result == DC_OK)
+			dc_result = dc_validate_stream(adev->dm.dc, stream);
 
 		if (dc_result != DC_OK) {
 			DRM_DEBUG_KMS("Mode %dx%d (clk %d) failed DC validation with error %d (%s)\n",
@@ -7560,7 +7564,7 @@ static void dm_encoder_helper_disable(struct drm_encoder *encoder)
 
 }
 
-static int convert_dc_color_depth_into_bpc (enum dc_color_depth display_color_depth)
+int convert_dc_color_depth_into_bpc(enum dc_color_depth display_color_depth)
 {
 	switch (display_color_depth) {
 		case COLOR_DEPTH_666:

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h

@@ -583,7 +583,6 @@ struct amdgpu_dm_connector {
 	struct drm_dp_mst_port *port;
 	struct amdgpu_dm_connector *mst_port;
 	struct drm_dp_aux *dsc_aux;
-
 	/* TODO see if we can merge with ddc_bus or make a dm_connector */
 	struct amdgpu_i2c_adapter *i2c;
 
@@ -747,4 +746,6 @@ int dm_atomic_get_state(struct drm_atomic_state *state,
 struct amdgpu_dm_connector *
 amdgpu_dm_find_first_crtc_matching_connector(struct drm_atomic_state *state,
 					     struct drm_crtc *crtc);
+
+int convert_dc_color_depth_into_bpc(enum dc_color_depth display_color_depth);
 #endif /* __AMDGPU_DM_H__ */

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c

@@ -1353,4 +1353,40 @@ bool pre_validate_dsc(struct drm_atomic_state *state,
 
 	return (ret == 0);
 }
+
 #endif
+
+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;
+
+	/* 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, false);
+	if (pbn > aconnector->port->full_pbn)
+		return DC_FAIL_BANDWIDTH_VALIDATE;
+
+	/* check is mst dsc output bandwidth branch_overall_throughput_0_mps */
+	switch (stream->timing.pixel_encoding) {
+	case PIXEL_ENCODING_RGB:
+	case PIXEL_ENCODING_YCBCR444:
+		branch_max_throughput_mps =
+			aconnector->dc_sink->dsc_caps.dsc_dec_caps.branch_overall_throughput_0_mps;
+		break;
+	case PIXEL_ENCODING_YCBCR422:
+	case PIXEL_ENCODING_YCBCR420:
+		branch_max_throughput_mps =
+			aconnector->dc_sink->dsc_caps.dsc_dec_caps.branch_overall_throughput_1_mps;
+		break;
+	default:
+		break;
+	}
+
+	if (branch_max_throughput_mps != 0 &&
+		((stream->timing.pix_clk_100hz / 10) >  branch_max_throughput_mps * 1000))
+		return DC_FAIL_BANDWIDTH_VALIDATE;
+
+	return DC_OK;
+}

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h

@@ -63,4 +63,8 @@ bool pre_validate_dsc(struct drm_atomic_state *state,
 		      struct dm_atomic_state **dm_state_ptr,
 		      struct dsc_mst_fairness_vars *vars);
 
+enum dc_status dm_dp_mst_is_port_support_mode(
+	struct amdgpu_dm_connector *aconnector,
+	struct dc_stream_state *stream);
+
 #endif