[PATCH 01/21] Partially revert "drm/amd/display: update add plane to context logic with a new algorithm"

[Hamza Mahfooz]

From: Wenjing Liu <wenjing.liu at amd.com>

This partially reverts commit e170066a4719 ("drm/amd/display: update add
plane to context logic with a new algorithm").

The new secondary pipe allocation logic triggers an issue with a
specific hardware state transition and causes a frame of corruption when
toggling between windowed MPO and ODM desktop only mode. Ideally hwss is
supposed to handle this scenario. We are temporarily reverting the logic
and investigate the root cause why this transition would cause
corruptions.

Reviewed-by: Martin Leung <martin.leung at amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz at amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu at amd.com>
---
 .../drm/amd/display/dc/dcn32/dcn32_resource.c | 118 +++++++++++++++++-
 1 file changed, 114 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.c b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.c
index 935cd23e6a01..f9d601c8c721 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.c
@@ -2564,18 +2564,128 @@ static int find_optimal_free_pipe_as_secondary_dpp_pipe(
 	return free_pipe_idx;
 }
 
+static struct pipe_ctx *find_idle_secondary_pipe_check_mpo(
+		struct resource_context *res_ctx,
+		const struct resource_pool *pool,
+		const struct pipe_ctx *primary_pipe)
+{
+	int i;
+	struct pipe_ctx *secondary_pipe = NULL;
+	struct pipe_ctx *next_odm_mpo_pipe = NULL;
+	int primary_index, preferred_pipe_idx;
+	struct pipe_ctx *old_primary_pipe = NULL;
+
+	/*
+	 * Modified from find_idle_secondary_pipe
+	 * With windowed MPO and ODM, we want to avoid the case where we want a
+	 *  free pipe for the left side but the free pipe is being used on the
+	 *  right side.
+	 * Add check on current_state if the primary_pipe is the left side,
+	 *  to check the right side ( primary_pipe->next_odm_pipe ) to see if
+	 *  it is using a pipe for MPO ( primary_pipe->next_odm_pipe->bottom_pipe )
+	 * - If so, then don't use this pipe
+	 * EXCEPTION - 3 plane ( 2 MPO plane ) case
+	 * - in this case, the primary pipe has already gotten a free pipe for the
+	 *  MPO window in the left
+	 * - when it tries to get a free pipe for the MPO window on the right,
+	 *  it will see that it is already assigned to the right side
+	 *  ( primary_pipe->next_odm_pipe ).  But in this case, we want this
+	 *  free pipe, since it will be for the right side.  So add an
+	 *  additional condition, that skipping the free pipe on the right only
+	 *  applies if the primary pipe has no bottom pipe currently assigned
+	 */
+	if (primary_pipe) {
+		primary_index = primary_pipe->pipe_idx;
+		old_primary_pipe = &primary_pipe->stream->ctx->dc->current_state->res_ctx.pipe_ctx[primary_index];
+		if ((old_primary_pipe->next_odm_pipe) && (old_primary_pipe->next_odm_pipe->bottom_pipe)
+			&& (!primary_pipe->bottom_pipe))
+			next_odm_mpo_pipe = old_primary_pipe->next_odm_pipe->bottom_pipe;
+
+		preferred_pipe_idx = (pool->pipe_count - 1) - primary_pipe->pipe_idx;
+		if ((res_ctx->pipe_ctx[preferred_pipe_idx].stream == NULL) &&
+			!(next_odm_mpo_pipe && next_odm_mpo_pipe->pipe_idx == preferred_pipe_idx)) {
+			secondary_pipe = &res_ctx->pipe_ctx[preferred_pipe_idx];
+			secondary_pipe->pipe_idx = preferred_pipe_idx;
+		}
+	}
+
+	/*
+	 * search backwards for the second pipe to keep pipe
+	 * assignment more consistent
+	 */
+	if (!secondary_pipe)
+		for (i = pool->pipe_count - 1; i >= 0; i--) {
+			if ((res_ctx->pipe_ctx[i].stream == NULL) &&
+				!(next_odm_mpo_pipe && next_odm_mpo_pipe->pipe_idx == i)) {
+				secondary_pipe = &res_ctx->pipe_ctx[i];
+				secondary_pipe->pipe_idx = i;
+				break;
+			}
+		}
+
+	return secondary_pipe;
+}
+
+static struct pipe_ctx *dcn32_acquire_idle_pipe_for_head_pipe_in_layer(
+		struct dc_state *state,
+		const struct resource_pool *pool,
+		struct dc_stream_state *stream,
+		const struct pipe_ctx *head_pipe)
+{
+	struct resource_context *res_ctx = &state->res_ctx;
+	struct pipe_ctx *idle_pipe, *pipe;
+	struct resource_context *old_ctx = &stream->ctx->dc->current_state->res_ctx;
+	int head_index;
+
+	if (!head_pipe)
+		ASSERT(0);
+
+	/*
+	 * Modified from dcn20_acquire_idle_pipe_for_layer
+	 * Check if head_pipe in old_context already has bottom_pipe allocated.
+	 * - If so, check if that pipe is available in the current context.
+	 * --  If so, reuse pipe from old_context
+	 */
+	head_index = head_pipe->pipe_idx;
+	pipe = &old_ctx->pipe_ctx[head_index];
+	if (pipe->bottom_pipe && res_ctx->pipe_ctx[pipe->bottom_pipe->pipe_idx].stream == NULL) {
+		idle_pipe = &res_ctx->pipe_ctx[pipe->bottom_pipe->pipe_idx];
+		idle_pipe->pipe_idx = pipe->bottom_pipe->pipe_idx;
+	} else {
+		idle_pipe = find_idle_secondary_pipe_check_mpo(res_ctx, pool, head_pipe);
+		if (!idle_pipe)
+			return NULL;
+	}
+
+	idle_pipe->stream = head_pipe->stream;
+	idle_pipe->stream_res.tg = head_pipe->stream_res.tg;
+	idle_pipe->stream_res.opp = head_pipe->stream_res.opp;
+
+	idle_pipe->plane_res.hubp = pool->hubps[idle_pipe->pipe_idx];
+	idle_pipe->plane_res.ipp = pool->ipps[idle_pipe->pipe_idx];
+	idle_pipe->plane_res.dpp = pool->dpps[idle_pipe->pipe_idx];
+	idle_pipe->plane_res.mpcc_inst = pool->dpps[idle_pipe->pipe_idx]->inst;
+
+	return idle_pipe;
+}
+
 struct pipe_ctx *dcn32_acquire_free_pipe_as_secondary_dpp_pipe(
 		const struct dc_state *cur_ctx,
 		struct dc_state *new_ctx,
 		const struct resource_pool *pool,
 		const struct pipe_ctx *opp_head_pipe)
 {
-	int free_pipe_idx =
-			find_optimal_free_pipe_as_secondary_dpp_pipe(
-					&cur_ctx->res_ctx, &new_ctx->res_ctx,
-					pool, opp_head_pipe);
+
+	int free_pipe_idx;
 	struct pipe_ctx *free_pipe;
 
+	if (!opp_head_pipe->stream->ctx->dc->config.enable_windowed_mpo_odm)
+		return dcn32_acquire_idle_pipe_for_head_pipe_in_layer(
+				new_ctx, pool, opp_head_pipe->stream, opp_head_pipe);
+
+	free_pipe_idx = find_optimal_free_pipe_as_secondary_dpp_pipe(
+					&cur_ctx->res_ctx, &new_ctx->res_ctx,
+					pool, opp_head_pipe);
 	if (free_pipe_idx >= 0) {
 		free_pipe = &new_ctx->res_ctx.pipe_ctx[free_pipe_idx];
 		free_pipe->pipe_idx = free_pipe_idx;
-- 
2.41.0