[PATCH AUTOSEL 5.0 175/262] drm/amd/display: Disconnect mpcc when changing tg

Sasha Levin
2019-03-27T19:19:58Z

From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>

[ Upstream commit 77476360f173c127c191bfe8ca8113130ef283b8 ]

[Why]
This fixes an mpc programming error for the following sequence of
atomic commits when pipe split is enabled:

Commit 1: CRTC0 (plane 4, plane 3)

Pipe 0: old_plane_state = A0, new_plane_state = A1, new_tg = T0
Pipe 1: old_plane_state = B0, new_plane_state = B1, new_tg = T0
Pipe 2: old_plane_state = A0, new_plane_state = A1, new_tg = T0
Pipe 3: old_plane_state = B0, new_plane_state = B1, new_tg = T0

Commit 2: CRTC0 (plane 3), CRTC1 (plane 2)

Pipe 0: old_plane_state = A1, new_plane_state = A2, new_tg = T0
Pipe 1: old_plane_state = B1, new_plane_state = B2, new_tg = T1
Pipe 2: old_plane_state = A1, new_plane_state = NULL, new_tg = NULL
Pipe 3: old_plane_state = B1, new_plane_state = NULL, new_tg = NULL

In the second commit the assertion for mpcc in use is hit because
mpcc disconnect never occurs for pipe 1. This is because the stream
changes for pipe 1 and the opp_list is empty.

This sequence occurs when running the
"igt@kms_plane_multiple@atomic-pipe-A-tiling-none" test with two
displays connected.

[How]
Expand the reset condition to include:

"old_pipe_ctx->stream_res.tg != new_pipe_ctx->stream_res.tg"

...but only when the plane state is non-NULL for both old and new.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@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/dcn10/dcn10_hw_sequencer.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
index 41883c981789..a684b38332ac 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
@@ -2334,9 +2334,10 @@ static void dcn10_apply_ctx_for_surface(
}
}

- if (!pipe_ctx->plane_state &&
- old_pipe_ctx->plane_state &&
- old_pipe_ctx->stream_res.tg == tg) {
+ if ((!pipe_ctx->plane_state ||
+ pipe_ctx->stream_res.tg != old_pipe_ctx->stream_res.tg) &&
+ old_pipe_ctx->plane_state &&
+ old_pipe_ctx->stream_res.tg == tg) {

dc->hwss.plane_atomic_disconnect(dc, old_pipe_ctx);
removed_pipe[i] = true;
--
2.19.1