drm/amd/display: add pipe reassignment prevention code to dcn3

Add code to gracefuly handle any pipe reassignment
occuring on dcn3 hardware. This should only happen when new
surfaces are used for an update rather than old ones updated.

Fixes: 69fc1f4b ("amd/drm/display: avoid dcn3 on flip opp change for slave pipes")
Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Reviewed-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c

@@ -1901,21 +1901,28 @@ static bool dcn30_split_stream_for_mpc_or_odm(
 
 static struct pipe_ctx *dcn30_find_split_pipe(
 		struct dc *dc,
-		struct dc_state *context)
+		struct dc_state *context,
+		int old_index)
 {
 	struct pipe_ctx *pipe = NULL;
 	int i;
 
-	for (i = dc->res_pool->pipe_count - 1; i >= 0; i--) {
-		if (dc->current_state->res_ctx.pipe_ctx[i].top_pipe == NULL
-				&& dc->current_state->res_ctx.pipe_ctx[i].prev_odm_pipe == NULL) {
-			if (context->res_ctx.pipe_ctx[i].stream == NULL) {
-				pipe = &context->res_ctx.pipe_ctx[i];
-				pipe->pipe_idx = i;
-				break;
+	if (old_index >= 0 && context->res_ctx.pipe_ctx[old_index].stream == NULL) {
+		pipe = &context->res_ctx.pipe_ctx[old_index];
+		pipe->pipe_idx = old_index;
+	}
+
+	if (!pipe)
+		for (i = dc->res_pool->pipe_count - 1; i >= 0; i--) {
+			if (dc->current_state->res_ctx.pipe_ctx[i].top_pipe == NULL
+					&& dc->current_state->res_ctx.pipe_ctx[i].prev_odm_pipe == NULL) {
+				if (context->res_ctx.pipe_ctx[i].stream == NULL) {
+					pipe = &context->res_ctx.pipe_ctx[i];
+					pipe->pipe_idx = i;
+					break;
+				}
 			}
 		}
-	}
 
 	/*
 	 * May need to fix pipes getting tossed from 1 opp to another on flip
@@ -2082,8 +2089,10 @@ static bool dcn30_internal_validate_bw(
 
 	for (i = 0, pipe_idx = -1; i < dc->res_pool->pipe_count; i++) {
 		struct pipe_ctx *pipe = &context->res_ctx.pipe_ctx[i];
+		struct pipe_ctx *old_pipe = &dc->current_state->res_ctx.pipe_ctx[i];
 		struct pipe_ctx *hsplit_pipe = NULL;
 		bool odm;
+		int old_index = -1;
 
 		if (!pipe->stream || newly_split[i])
 			continue;
@@ -2095,7 +2104,20 @@ static bool dcn30_internal_validate_bw(
 			continue;
 
 		if (split[i]) {
-			hsplit_pipe = dcn30_find_split_pipe(dc, context);
+			if (odm) {
+				if (split[i] == 4 && old_pipe->next_odm_pipe->next_odm_pipe)
+					old_index = old_pipe->next_odm_pipe->next_odm_pipe->pipe_idx;
+				else if (old_pipe->next_odm_pipe)
+					old_index = old_pipe->next_odm_pipe->pipe_idx;
+			} else {
+				if (split[i] == 4 && old_pipe->bottom_pipe->bottom_pipe &&
+						old_pipe->bottom_pipe->bottom_pipe->plane_state == old_pipe->plane_state)
+					old_index = old_pipe->bottom_pipe->bottom_pipe->pipe_idx;
+				else if (old_pipe->bottom_pipe &&
+						old_pipe->bottom_pipe->plane_state == old_pipe->plane_state)
+					old_index = old_pipe->bottom_pipe->pipe_idx;
+			}
+			hsplit_pipe = dcn30_find_split_pipe(dc, context, old_index);
 			ASSERT(hsplit_pipe);
 			if (!hsplit_pipe)
 				goto validate_fail;
@@ -2109,8 +2131,16 @@ static bool dcn30_internal_validate_bw(
 			repopulate_pipes = true;
 		}
 		if (split[i] == 4) {
-			struct pipe_ctx *pipe_4to1 = dcn30_find_split_pipe(dc, context);
+			struct pipe_ctx *pipe_4to1;
 
+			if (odm && old_pipe->next_odm_pipe)
+				old_index = old_pipe->next_odm_pipe->pipe_idx;
+			else if (!odm && old_pipe->bottom_pipe &&
+						old_pipe->bottom_pipe->plane_state == old_pipe->plane_state)
+				old_index = old_pipe->bottom_pipe->pipe_idx;
+			else
+				old_index = -1;
+			pipe_4to1 = dcn30_find_split_pipe(dc, context, old_index);
 			ASSERT(pipe_4to1);
 			if (!pipe_4to1)
 				goto validate_fail;
@@ -2120,7 +2150,14 @@ static bool dcn30_internal_validate_bw(
 				goto validate_fail;
 			newly_split[pipe_4to1->pipe_idx] = true;
 
-			pipe_4to1 = dcn30_find_split_pipe(dc, context);
+			if (odm && old_pipe->next_odm_pipe->next_odm_pipe->next_odm_pipe)
+				old_index = old_pipe->next_odm_pipe->next_odm_pipe->next_odm_pipe->pipe_idx;
+			else if (!odm && old_pipe->bottom_pipe->bottom_pipe->bottom_pipe &&
+						old_pipe->bottom_pipe->bottom_pipe->bottom_pipe->plane_state == old_pipe->plane_state)
+				old_index = old_pipe->bottom_pipe->bottom_pipe->bottom_pipe->pipe_idx;
+			else
+				old_index = -1;
+			pipe_4to1 = dcn30_find_split_pipe(dc, context, old_index);
 			ASSERT(pipe_4to1);
 			if (!pipe_4to1)
 				goto validate_fail;