4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ 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@xxxxxxx> Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@xxxxxxx> Reviewed-by: Tony Cheng <Tony.Cheng@xxxxxxx> Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 4058b59d9bea..a0355709abd1 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 @@ -2336,9 +2336,10 @@ 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