From: David Francis David.Francis@amd.com

[ Upstream commit c238bfe0be9ef7420f7669a69e27c8c8f4d8a568 ]

[Why] On some compositors, with two monitors attached, VT terminal switch can cause a graphical issue by the following means:

There are two streams, one for each monitor. Each stream has one plane

current state: M1:S1->P1 M2:S2->P2

The user calls for a terminal switch and a commit is made to change both planes to linear swizzle mode. In atomic check, a new dc_state is constructed with new planes on each stream

new state: M1:S1->P3 M2:S2->P4

In commit tail, each stream is committed, one at a time. The first stream (S1) updates properly, triggerring a full update and replacing the state

current state: M1:S1->P3 M2:S2->P4

The update for S2 comes in, but dc detects that there is no difference between the stream and plane in the new and current states, and so triggers a fast update. The fast update does not program swizzle, so the second monitor is corrupted

[How] Add a flag to dc_plane_state that forces full updates

When a stream undergoes a full update, set this flag on all changed planes, then clear it on the current stream

Subsequent streams will get full updates as a result

Signed-off-by: David Francis David.Francis@amd.com Signed-off-by: Nicholas Kazlauskas nicholas.kazlauskas@amd.com Reviewed-by: Roman Li Roman.Li@amd.com Acked-by: Bhawanpreet Lakha <Bhawanpreet Lakha@amd.com> Acked-by: Nicholas Kazlauskas Nicholas.Kazlauskas@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/core/dc.c | 19 +++++++++++++++++++ drivers/gpu/drm/amd/display/dc/dc.h | 3 +++ 2 files changed, 22 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c index bb0cda727605..e3f5e5d6f0c1 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c @@ -1213,6 +1213,11 @@ static enum surface_update_type det_surface_update(const struct dc *dc, return UPDATE_TYPE_FULL; }

+ if (u->surface->force_full_update) { + update_flags->bits.full_update = 1; + return UPDATE_TYPE_FULL; + } + type = get_plane_info_update_type(u); elevate_update_type(&overall_type, type);

@@ -1467,6 +1472,14 @@ void dc_commit_updates_for_stream(struct dc *dc, }

dc_resource_state_copy_construct(state, context); + + for (i = 0; i < dc->res_pool->pipe_count; i++) { + struct pipe_ctx *new_pipe = &context->res_ctx.pipe_ctx[i]; + struct pipe_ctx *old_pipe = &dc->current_state->res_ctx.pipe_ctx[i]; + + if (new_pipe->plane_state && new_pipe->plane_state != old_pipe->plane_state) + new_pipe->plane_state->force_full_update = true; + } }

@@ -1510,6 +1523,12 @@ void dc_commit_updates_for_stream(struct dc *dc, dc->current_state = context; dc_release_state(old);

+ for (i = 0; i < dc->res_pool->pipe_count; i++) { + struct pipe_ctx *pipe_ctx = &context->res_ctx.pipe_ctx[i]; + + if (pipe_ctx->plane_state && pipe_ctx->stream == stream) + pipe_ctx->plane_state->force_full_update = false; + } } /*let's use current_state to update watermark etc*/ if (update_type >= UPDATE_TYPE_FULL) diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h index 6c9990bef267..4094b4f50111 100644 --- a/drivers/gpu/drm/amd/display/dc/dc.h +++ b/drivers/gpu/drm/amd/display/dc/dc.h @@ -505,6 +505,9 @@ struct dc_plane_state { struct dc_plane_status status; struct dc_context *ctx;

+ /* HACK: Workaround for forcing full reprogramming under some conditions */ + bool force_full_update; + /* private to dc_surface.c */ enum dc_irq_source irq_source; struct kref refcount;