drm/amd/display: Map DSC resources 1-to-1 if numbers of OPPs and DSCs are equal

[why]
On ASICs where number of DSCs is the same as OPPs there's no need
for DSC resource management. Mappping 1-to-1 fixes mode-set- or S3-
-related issues for such platforms.

[how]
Map DSC resources 1-to-1 to pipes only if number of OPPs is the same
as number of DSCs. This will still keep other ASICs working.
A follow-up patch to fix mode-set issues on those ASICs will be
required if testing shows issues with mode set.

Signed-off-by: Nikola Cornij <nikola.cornij@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
index 2a158ff..322556c 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
@@ -1524,13 +1524,20 @@ enum dc_status dcn20_build_mapped_resource(const struct dc *dc, struct dc_state
 
 static void acquire_dsc(struct resource_context *res_ctx,
                        const struct resource_pool *pool,
-                       struct display_stream_compressor **dsc)
+                       struct display_stream_compressor **dsc,
+                       int pipe_idx)
 {
        int i;
 
        ASSERT(*dsc == NULL);
        *dsc = NULL;
 
+       if (pool->res_cap->num_dsc == pool->res_cap->num_opp) {
+               *dsc = pool->dscs[pipe_idx];
+               res_ctx->is_dsc_acquired[pipe_idx] = true;
+               return;
+       }
+
        /* Find first free DSC */
        for (i = 0; i < pool->res_cap->num_dsc; i++)
                if (!res_ctx->is_dsc_acquired[i]) {
@@ -1571,7 +1578,7 @@ static enum dc_status add_dsc_to_stream_resource(struct dc *dc,
                if (pipe_ctx->stream != dc_stream)
                        continue;
 
-               acquire_dsc(&dc_ctx->res_ctx, pool, &pipe_ctx->stream_res.dsc);
+               acquire_dsc(&dc_ctx->res_ctx, pool, &pipe_ctx->stream_res.dsc, i);
 
                /* The number of DSCs can be less than the number of pipes */
                if (!pipe_ctx->stream_res.dsc) {
@@ -1763,7 +1770,7 @@ bool dcn20_split_stream_for_odm(
        }
        next_odm_pipe->stream_res.opp = pool->opps[next_odm_pipe->pipe_idx];
        if (next_odm_pipe->stream->timing.flags.DSC == 1) {
-               acquire_dsc(res_ctx, pool, &next_odm_pipe->stream_res.dsc);
+               acquire_dsc(res_ctx, pool, &next_odm_pipe->stream_res.dsc, next_odm_pipe->pipe_idx);
                ASSERT(next_odm_pipe->stream_res.dsc);
                if (next_odm_pipe->stream_res.dsc == NULL)
                        return false;