From: Nicholas Kazlauskas nicholas.kazlauskas@amd.com
[ Upstream commit 21ffcc94d5b3dc024fedac700f1e7f9dacf4ab4f ]
[Why] DC configures the GSL group for the pipe when pipe_split is enabled and we're switching flip types (buffered <-> immediate flip) on DCN2.
In order to record what GSL group the pipe is using DC stores it in the pipe's stream_res. DM is not aware of this internal grouping, nor is DC resource.
So when DM creates a dc_state context and passes it to DC the current GSL group is lost - DM never knew about it in the first place.
After 3 immediate flips we run out of GSL groups and we're no longer able to correctly perform *any* flip for multi-pipe scenarios.
[How] The gsl_group needs to be copied to the new context.
DM has no insight into GSL grouping and could even potentially create a brand new context without referencing current hardware state. So this makes the most sense to have happen in DC.
There are two places where DC can apply a new context: - dc_commit_state - dc_commit_updates_for_stream
But what's shared between both of these is apply_ctx_for_surface.
This logic only matters for DCN2, so it can be placed in dcn20_apply_ctx_for_surface. Before doing any locking (where the GSL group is setup) we can copy over the GSL groups before committing the new context.
Signed-off-by: Nicholas Kazlauskas nicholas.kazlauskas@amd.com Reviewed-by: Hersen Wu hersen.wu@amd.com Acked-by: Leo Li sunpeng.li@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c index 2627e0a98a96a..f8abe98a576be 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c @@ -1319,6 +1319,18 @@ static void dcn20_apply_ctx_for_surface( if (!top_pipe_to_program) return;
+ /* Carry over GSL groups in case the context is changing. */ + for (i = 0; i < dc->res_pool->pipe_count; i++) { + struct pipe_ctx *pipe_ctx = &context->res_ctx.pipe_ctx[i]; + struct pipe_ctx *old_pipe_ctx = + &dc->current_state->res_ctx.pipe_ctx[i]; + + if (pipe_ctx->stream == stream && + pipe_ctx->stream == old_pipe_ctx->stream) + pipe_ctx->stream_res.gsl_group = + old_pipe_ctx->stream_res.gsl_group; + } + tg = top_pipe_to_program->stream_res.tg;
interdependent_update = top_pipe_to_program->plane_state &&