drm/amd/display: Add DPIA Link Encoder Assignment Fix

For DPIA we should have preferred DIG assignment based on DPIA selected
as per the ASIC design.
Reviewed-by: George Shen <george.shen@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Mustapha Ghaddar <mghaddar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc_link_enc_cfg.c

@@ -169,11 +169,23 @@ static void add_link_enc_assignment(
 /* Return first available DIG link encoder. */
 static enum engine_id find_first_avail_link_enc(
 		const struct dc_context *ctx,
-		const struct dc_state *state)
+		const struct dc_state *state,
+		enum engine_id eng_id_requested)
 {
 	enum engine_id eng_id = ENGINE_ID_UNKNOWN;
 	int i;
 
+	if (eng_id_requested != ENGINE_ID_UNKNOWN) {
+
+		for (i = 0; i < ctx->dc->res_pool->res_cap->num_dig_link_enc; i++) {
+			eng_id = state->res_ctx.link_enc_cfg_ctx.link_enc_avail[i];
+			if (eng_id == eng_id_requested)
+				return eng_id;
+		}
+	}
+
+	eng_id = ENGINE_ID_UNKNOWN;
+
 	for (i = 0; i < ctx->dc->res_pool->res_cap->num_dig_link_enc; i++) {
 		eng_id = state->res_ctx.link_enc_cfg_ctx.link_enc_avail[i];
 		if (eng_id != ENGINE_ID_UNKNOWN)
@@ -287,7 +299,7 @@ void link_enc_cfg_link_encs_assign(
 		struct dc_stream_state *streams[],
 		uint8_t stream_count)
 {
-	enum engine_id eng_id = ENGINE_ID_UNKNOWN;
+	enum engine_id eng_id = ENGINE_ID_UNKNOWN, eng_id_req = ENGINE_ID_UNKNOWN;
 	int i;
 	int j;
 
@@ -377,8 +389,15 @@ void link_enc_cfg_link_encs_assign(
 		 * assigned to that endpoint.
 		 */
 		link_enc = get_link_enc_used_by_link(state, stream->link);
-		if (link_enc == NULL)
-			eng_id = find_first_avail_link_enc(stream->ctx, state);
+		if (link_enc == NULL) {
+
+			if (stream->link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA &&
+					stream->link->dpia_preferred_eng_id != ENGINE_ID_UNKNOWN)
+				eng_id_req = stream->link->dpia_preferred_eng_id;
+
+			if (eng_id == ENGINE_ID_UNKNOWN)
+				eng_id = find_first_avail_link_enc(stream->ctx, state, eng_id_req);
+		}
 		else
 			eng_id =  link_enc->preferred_engine;
 
@@ -402,7 +421,9 @@ void link_enc_cfg_link_encs_assign(
 			DC_LOG_DEBUG("%s: CUR %s(%d) - enc_id(%d)\n",
 					__func__,
 					assignment.ep_id.ep_type == DISPLAY_ENDPOINT_PHY ? "PHY" : "DPIA",
-					assignment.ep_id.link_id.enum_id - 1,
+					assignment.ep_id.ep_type == DISPLAY_ENDPOINT_PHY ?
+							assignment.ep_id.link_id.enum_id :
+							assignment.ep_id.link_id.enum_id - 1,
 					assignment.eng_id);
 	}
 	for (i = 0; i < MAX_PIPES; i++) {
@@ -413,7 +434,9 @@ void link_enc_cfg_link_encs_assign(
 			DC_LOG_DEBUG("%s: NEW %s(%d) - enc_id(%d)\n",
 					__func__,
 					assignment.ep_id.ep_type == DISPLAY_ENDPOINT_PHY ? "PHY" : "DPIA",
-					assignment.ep_id.link_id.enum_id - 1,
+					assignment.ep_id.ep_type == DISPLAY_ENDPOINT_PHY ?
+							assignment.ep_id.link_id.enum_id :
+							assignment.ep_id.link_id.enum_id - 1,
 					assignment.eng_id);
 	}
 

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

@@ -1496,6 +1496,7 @@ struct dc_link {
 	 * object creation.
 	 */
 	enum engine_id eng_id;
+	enum engine_id dpia_preferred_eng_id;
 
 	bool test_pattern_enabled;
 	enum dp_test_pattern current_test_pattern;

drivers/gpu/drm/amd/display/dc/dcn314/dcn314_resource.c

@@ -1032,6 +1032,28 @@ static const struct dce_i2c_mask i2c_masks = {
 		I2C_COMMON_MASK_SH_LIST_DCN30(_MASK)
 };
 
+/* ========================================================== */
+
+/*
+ * DPIA index | Preferred Encoder     |    Host Router
+ *   0        |      C                |       0
+ *   1        |      First Available  |       0
+ *   2        |      D                |       1
+ *   3        |      First Available  |       1
+ */
+/* ========================================================== */
+static const enum engine_id dpia_to_preferred_enc_id_table[] = {
+		ENGINE_ID_DIGC,
+		ENGINE_ID_DIGC,
+		ENGINE_ID_DIGD,
+		ENGINE_ID_DIGD
+};
+
+static enum engine_id dcn314_get_preferred_eng_id_dpia(unsigned int dpia_index)
+{
+	return dpia_to_preferred_enc_id_table[dpia_index];
+}
+
 static struct dce_i2c_hw *dcn31_i2c_hw_create(
 	struct dc_context *ctx,
 	uint32_t inst)
@@ -1785,6 +1807,7 @@ static struct resource_funcs dcn314_res_pool_funcs = {
 	.update_bw_bounding_box = dcn314_update_bw_bounding_box,
 	.patch_unknown_plane_state = dcn20_patch_unknown_plane_state,
 	.get_panel_config_defaults = dcn314_get_panel_config_defaults,
+	.get_preferred_eng_id_dpia = dcn314_get_preferred_eng_id_dpia,
 };
 
 static struct clock_source *dcn30_clock_source_create(

drivers/gpu/drm/amd/display/dc/inc/core_types.h

@@ -65,6 +65,7 @@ struct resource_context;
 struct clk_bw_params;
 
 struct resource_funcs {
+	enum engine_id (*get_preferred_eng_id_dpia)(unsigned int dpia_index);
 	void (*destroy)(struct resource_pool **pool);
 	void (*link_init)(struct dc_link *link);
 	struct panel_cntl*(*panel_cntl_create)(

drivers/gpu/drm/amd/display/dc/link/link_factory.c

@@ -792,6 +792,10 @@ static bool construct_dpia(struct dc_link *link,
 	/* Set dpia port index : 0 to number of dpia ports */
 	link->ddc_hw_inst = init_params->connector_index;
 
+	// Assign Dpia preferred eng_id
+	if (link->dc->res_pool->funcs->get_preferred_eng_id_dpia)
+		link->dpia_preferred_eng_id = link->dc->res_pool->funcs->get_preferred_eng_id_dpia(link->ddc_hw_inst);
+
 	/* TODO: Create link encoder */
 
 	link->psr_settings.psr_version = DC_PSR_VERSION_UNSUPPORTED;