drm/amd/display: Require immediate flip support for DCN3.1 planes

[Why]
Immediate flip can be enabled dynamically and has higher BW requirements
when validating which voltage mode to use.

If we validate when it's not set then potentially DCFCLK will be too low
and we will underflow.

[How]
DM always requires support so always require it as part of DML input
parameters.

This can't be enabled unconditionally on older ASIC because it blocks
some expected modes so only target DCN3.1 for now.

Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Agustin Gutierrez Sanchez <agustin.gutierrez@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c
index a2e40405c97d745d3e7ef1ebfba23b5f7a42f745..c9d3d691f4c6aacced2eb330d0fe2d5450df8286 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c
@@ -1778,6 +1778,13 @@ static int dcn31_populate_dml_pipes_from_context(
                pipe = &res_ctx->pipe_ctx[i];
                timing = &pipe->stream->timing;
 
+               /*
+                * Immediate flip can be set dynamically after enabling the plane.
+                * We need to require support for immediate flip or underflow can be
+                * intermittently experienced depending on peak b/w requirements.
+                */
+               pipes[pipe_cnt].pipe.src.immediate_flip = true;
+
                pipes[pipe_cnt].pipe.src.unbounded_req_mode = false;
                pipes[pipe_cnt].pipe.src.gpuvm = true;
                pipes[pipe_cnt].pipe.src.dcc_fraction_of_zs_req_luma = 0;