drm/amd/display: Modify Pipe Selection for Policy for ODM

[Why]
There are certain cases during a transition to ODM that might cause
corruption on the display. This occurs when we choose certain pipes in a
particular state.

[How]
We now will store the pipe indexes of the any pipes that might be
problematic to switch to during an ODM transition, and only use them as
a last resort.

Reviewed-by: Dmytro Laktyushkin <dmytro.laktyushkin@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Qingqing Zhuo <Qingqing.Zhuo@amd.com>
Signed-off-by: Saaem Rizvi <syedsaaem.rizvi@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml2_dc_resource_mgmt.c b/drivers/gpu/drm/amd/display/dc/dml2/dml2_dc_resource_mgmt.c
index e22b510..36baf35 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dml2/dml2_dc_resource_mgmt.c
+++ b/drivers/gpu/drm/amd/display/dc/dml2/dml2_dc_resource_mgmt.c
@@ -213,6 +213,82 @@ static bool is_pipe_free(const struct pipe_ctx *pipe)
        return false;
 }
 
+static unsigned int find_preferred_pipe_candidates(const struct dc_state *existing_state,
+       const int pipe_count,
+       const unsigned int stream_id,
+       unsigned int *preferred_pipe_candidates)
+{
+       unsigned int num_preferred_candidates = 0;
+       int i;
+
+       /* There is only one case which we consider for adding a pipe to the preferred
+        * pipe candidate array:
+        *
+        * 1. If the existing stream id of the pipe is equivalent to the stream id
+        * of the stream we are trying to achieve MPC/ODM combine for. This allows
+        * us to minimize the changes in pipe topology during the transition.
+        *
+        * However this condition comes with a caveat. We need to ignore pipes that will
+        * require a change in OPP but still have the same stream id. For example during
+        * an MPC to ODM transiton.
+        */
+       if (existing_state) {
+               for (i = 0; i < pipe_count; i++) {
+                       if (existing_state->res_ctx.pipe_ctx[i].stream && existing_state->res_ctx.pipe_ctx[i].stream->stream_id == stream_id) {
+                               if (existing_state->res_ctx.pipe_ctx[i].plane_res.hubp &&
+                                       existing_state->res_ctx.pipe_ctx[i].plane_res.hubp->opp_id != i)
+                                       continue;
+
+                               preferred_pipe_candidates[num_preferred_candidates++] = i;
+                       }
+               }
+       }
+
+       return num_preferred_candidates;
+}
+
+static unsigned int find_last_resort_pipe_candidates(const struct dc_state *existing_state,
+       const int pipe_count,
+       const unsigned int stream_id,
+       unsigned int *last_resort_pipe_candidates)
+{
+       unsigned int num_last_resort_candidates = 0;
+       int i;
+
+       /* There are two cases where we would like to add a given pipe into the last
+        * candidate array:
+        *
+        * 1. If the pipe requires a change in OPP, for example during an MPC
+        * to ODM transiton.
+        *
+        * 2. If the pipe already has an enabled OTG.
+        */
+       if (existing_state) {
+               for (i  = 0; i < pipe_count; i++) {
+                       if ((existing_state->res_ctx.pipe_ctx[i].plane_res.hubp &&
+                               existing_state->res_ctx.pipe_ctx[i].plane_res.hubp->opp_id != i) ||
+                               existing_state->res_ctx.pipe_ctx[i].stream_res.tg)
+                               last_resort_pipe_candidates[num_last_resort_candidates++] = i;
+               }
+       }
+
+       return num_last_resort_candidates;
+}
+
+static bool is_pipe_in_candidate_array(const unsigned int pipe_idx,
+       const unsigned int *candidate_array,
+       const unsigned int candidate_array_size)
+{
+       int i;
+
+       for (i = 0; i < candidate_array_size; i++) {
+               if (candidate_array[i] == pipe_idx)
+                       return true;
+       }
+
+       return false;
+}
+
 static bool find_more_pipes_for_stream(struct dml2_context *ctx,
        struct dc_state *state, // The state we want to find a free mapping in
        unsigned int stream_id, // The stream we want this pipe to drive
@@ -222,16 +298,18 @@ static bool find_more_pipes_for_stream(struct dml2_context *ctx,
        const struct dc_state *existing_state) // The state (optional) that we want to minimize remapping relative to
 {
        struct pipe_ctx *pipe = NULL;
-       unsigned int preferred_pipe_candidates[MAX_PIPES];
+       unsigned int preferred_pipe_candidates[MAX_PIPES] = {0};
+       unsigned int last_resort_pipe_candidates[MAX_PIPES] = {0};
        unsigned int num_preferred_candidates = 0;
+       unsigned int num_last_resort_candidates = 0;
        int i;
 
        if (existing_state) {
-               // To minimize prioritize candidates from existing stream
-               for (i = 0; i < ctx->config.dcn_pipe_count; i++) {
-                       if (existing_state->res_ctx.pipe_ctx[i].stream && existing_state->res_ctx.pipe_ctx[i].stream->stream_id == stream_id)
-                               preferred_pipe_candidates[num_preferred_candidates++] = existing_state->res_ctx.pipe_ctx[i].pipe_idx;
-               }
+               num_preferred_candidates =
+                       find_preferred_pipe_candidates(existing_state, ctx->config.dcn_pipe_count, stream_id, preferred_pipe_candidates);
+
+               num_last_resort_candidates =
+                       find_last_resort_pipe_candidates(existing_state, ctx->config.dcn_pipe_count, stream_id, last_resort_pipe_candidates);
        }
 
        // First see if any of the preferred are unmapped, and choose those instead
@@ -247,6 +325,11 @@ static bool find_more_pipes_for_stream(struct dml2_context *ctx,
 
        // We like to pair pipes starting from the higher order indicies for combining
        for (i = ctx->config.dcn_pipe_count - 1; pipes_needed > 0 && i >= 0; i--) {
+               // Ignore any pipes that are the preferred or last resort candidate
+               if (is_pipe_in_candidate_array(i, preferred_pipe_candidates, num_preferred_candidates) ||
+                       is_pipe_in_candidate_array(i, last_resort_pipe_candidates, num_last_resort_candidates))
+                       continue;
+
                pipe = &state->res_ctx.pipe_ctx[i];
                if (!is_plane_using_pipe(pipe)) {
                        pipes_needed--;
@@ -256,6 +339,17 @@ static bool find_more_pipes_for_stream(struct dml2_context *ctx,
                }
        }
 
+       // Only use the last resort pipe candidates as a last resort
+       for (i = 0; pipes_needed > 0 && i < num_last_resort_candidates; i++) {
+               pipe = &state->res_ctx.pipe_ctx[last_resort_pipe_candidates[i]];
+               if (!is_plane_using_pipe(pipe)) {
+                       pipes_needed--;
+                       // TODO: This doens't make sense really, pipe_idx should always be valid
+                       pipe->pipe_idx = last_resort_pipe_candidates[i];
+                       assigned_pipes[(*assigned_pipe_count)++] = pipe->pipe_idx;
+               }
+       }
+
        ASSERT(pipes_needed <= 0); // Validation should prevent us from building a pipe context that exceeds the number of HW resoruces available
 
        return pipes_needed <= 0;
@@ -270,16 +364,18 @@ static bool find_more_free_pipes(struct dml2_context *ctx,
        const struct dc_state *existing_state) // The state (optional) that we want to minimize remapping relative to
 {
        struct pipe_ctx *pipe = NULL;
-       unsigned int preferred_pipe_candidates[MAX_PIPES];
+       unsigned int preferred_pipe_candidates[MAX_PIPES] = {0};
+       unsigned int last_resort_pipe_candidates[MAX_PIPES] = {0};
        unsigned int num_preferred_candidates = 0;
+       unsigned int num_last_resort_candidates = 0;
        int i;
 
        if (existing_state) {
-               // To minimize prioritize candidates from existing stream
-               for (i = 0; i < ctx->config.dcn_pipe_count; i++) {
-                       if (existing_state->res_ctx.pipe_ctx[i].stream && existing_state->res_ctx.pipe_ctx[i].stream->stream_id == stream_id)
-                               preferred_pipe_candidates[num_preferred_candidates++] = existing_state->res_ctx.pipe_ctx[i].pipe_idx;
-               }
+               num_preferred_candidates =
+                       find_preferred_pipe_candidates(existing_state, ctx->config.dcn_pipe_count, stream_id, preferred_pipe_candidates);
+
+               num_last_resort_candidates =
+                       find_last_resort_pipe_candidates(existing_state, ctx->config.dcn_pipe_count, stream_id, last_resort_pipe_candidates);
        }
 
        // First see if any of the preferred are unmapped, and choose those instead
@@ -295,6 +391,11 @@ static bool find_more_free_pipes(struct dml2_context *ctx,
 
        // We like to pair pipes starting from the higher order indicies for combining
        for (i = ctx->config.dcn_pipe_count - 1; pipes_needed > 0 && i >= 0; i--) {
+               // Ignore any pipes that are the preferred or last resort candidate
+               if (is_pipe_in_candidate_array(i, preferred_pipe_candidates, num_preferred_candidates) ||
+                       is_pipe_in_candidate_array(i, last_resort_pipe_candidates, num_last_resort_candidates))
+                       continue;
+
                pipe = &state->res_ctx.pipe_ctx[i];
                if (is_pipe_free(pipe)) {
                        pipes_needed--;
@@ -304,6 +405,17 @@ static bool find_more_free_pipes(struct dml2_context *ctx,
                }
        }
 
+       // Only use the last resort pipe candidates as a last resort
+       for (i = 0; pipes_needed > 0 && i < num_last_resort_candidates; i++) {
+               pipe = &state->res_ctx.pipe_ctx[last_resort_pipe_candidates[i]];
+               if (is_pipe_free(pipe)) {
+                       pipes_needed--;
+                       // TODO: This doens't make sense really, pipe_idx should always be valid
+                       pipe->pipe_idx = last_resort_pipe_candidates[i];
+                       assigned_pipes[(*assigned_pipe_count)++] = pipe->pipe_idx;
+               }
+       }
+
        ASSERT(pipes_needed == 0); // Validation should prevent us from building a pipe context that exceeds the number of HW resoruces available
 
        return pipes_needed == 0;
@@ -465,7 +577,7 @@ static struct pipe_ctx *assign_pipes_to_stream(struct dml2_context *ctx, struct
        struct pipe_ctx *master_pipe;
        unsigned int pipes_needed;
        unsigned int pipes_assigned;
-       unsigned int pipes[MAX_PIPES];
+       unsigned int pipes[MAX_PIPES] = {0};
        unsigned int next_pipe_to_assign;
        int odm_slice;
 
@@ -502,7 +614,7 @@ static struct pipe_ctx *assign_pipes_to_plane(struct dml2_context *ctx, struct d
        unsigned int plane_id;
        unsigned int pipes_needed;
        unsigned int pipes_assigned;
-       unsigned int pipes[MAX_PIPES];
+       unsigned int pipes[MAX_PIPES] = {0};
        unsigned int next_pipe_to_assign;
        int odm_slice, mpc_slice;