[PATCH 6.1 1000/1146] drm/amd/display: Use min transition for SubVP into MPO

Greg Kroah-Hartman
2022-12-28T16:52:11Z

From: Alvin Lee <Alvin.Lee2@amd.com>

[ Upstream commit 9e7d03e8b046c84e1b2973a29cd800495a5a2f09 ]

[Description]
- For SubVP transitioning into MPO, we want to
use a minimal transition to prevent transient
underflow
- Transitioning a phantom pipe directly into a
"real" pipe can result in underflow due to the
HUBP still having it's "phantom" programming
when HUBP is unblanked (have to wait for next
VUPDATE of the new OTG)
- Also ensure subvp pipe lock is acquired early
enough for programming in dc_commit_state_no_check
- When disabling phantom planes, enable phantom OTG
first so the disable gets the double buffer update

Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Alan Liu <HaoPing.Liu@amd.com>
Signed-off-by: Alvin Lee <Alvin.Lee2@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@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 | 43 +++++++++++-------------
1 file changed, 20 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 5c00907099c1..5260ad6de803 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -1070,6 +1070,7 @@ static void disable_dangling_plane(struct dc *dc, struct dc_state *context)
int i, j;
struct dc_state *dangling_context = dc_create_state(dc);
struct dc_state *current_ctx;
+ struct pipe_ctx *pipe;

if (dangling_context == NULL)
return;
@@ -1112,6 +1113,16 @@ static void disable_dangling_plane(struct dc *dc, struct dc_state *context)
}

if (should_disable && old_stream) {
+ pipe = &dc->current_state->res_ctx.pipe_ctx[i];
+ /* When disabling plane for a phantom pipe, we must turn on the
+ * phantom OTG so the disable programming gets the double buffer
+ * update. Otherwise the pipe will be left in a partially disabled
+ * state that can result in underflow or hang when enabling it
+ * again for different use.
+ */
+ if (old_stream->mall_stream_config.type == SUBVP_PHANTOM) {
+ pipe->stream_res.tg->funcs->enable_crtc(pipe->stream_res.tg);
+ }
dc_rem_all_planes_for_stream(dc, old_stream, dangling_context);
disable_all_writeback_pipes_for_stream(dc, old_stream, dangling_context);

@@ -1760,6 +1771,12 @@ static enum dc_status dc_commit_state_no_check(struct dc *dc, struct dc_state *c
context->stream_count == 0)
dc->hwss.prepare_bandwidth(dc, context);

+ /* When SubVP is active, all HW programming must be done while
+ * SubVP lock is acquired
+ */
+ if (dc->hwss.subvp_pipe_control_lock)
+ dc->hwss.subvp_pipe_control_lock(dc, context, true, true, NULL, subvp_prev_use);
+
if (dc->debug.enable_double_buffered_dsc_pg_support)
dc->hwss.update_dsc_pg(dc, context, false);

@@ -1787,9 +1804,6 @@ static enum dc_status dc_commit_state_no_check(struct dc *dc, struct dc_state *c
dc->hwss.wait_for_mpcc_disconnect(dc, dc->res_pool, pipe);
}

- if (dc->hwss.subvp_pipe_control_lock)
- dc->hwss.subvp_pipe_control_lock(dc, context, true, true, NULL, subvp_prev_use);
-
result = dc->hwss.apply_ctx_to_hw(dc, context);

if (result != DC_OK) {
@@ -3576,7 +3590,6 @@ static bool could_mpcc_tree_change_for_active_pipes(struct dc *dc,

struct dc_stream_status *cur_stream_status = stream_get_status(dc->current_state, stream);
bool force_minimal_pipe_splitting = false;
- uint32_t i;

*is_plane_addition = false;

@@ -3608,27 +3621,11 @@ static bool could_mpcc_tree_change_for_active_pipes(struct dc *dc,
}
}

- /* For SubVP pipe split case when adding MPO video
- * we need to add a minimal transition. In this case
- * there will be 2 streams (1 main stream, 1 phantom
- * stream).
+ /* For SubVP when adding MPO video we need to add a minimal transition.
*/
- if (cur_stream_status &&
- dc->current_state->stream_count == 2 &&
- stream->mall_stream_config.type == SUBVP_MAIN) {
- bool is_pipe_split = false;
-
- for (i = 0; i < dc->res_pool->pipe_count; i++) {
- if (dc->current_state->res_ctx.pipe_ctx[i].stream == stream &&
- (dc->current_state->res_ctx.pipe_ctx[i].bottom_pipe ||
- dc->current_state->res_ctx.pipe_ctx[i].next_odm_pipe)) {
- is_pipe_split = true;
- break;
- }
- }
-
+ if (cur_stream_status && stream->mall_stream_config.type == SUBVP_MAIN) {
/* determine if minimal transition is required due to SubVP*/
- if (surface_count > 0 && is_pipe_split) {
+ if (surface_count > 0) {
if (cur_stream_status->plane_count > surface_count) {
force_minimal_pipe_splitting = true;
} else if (cur_stream_status->plane_count < surface_count) {
--
2.35.1