[PATCH 18/19] drm/amd/display: fix incorrect odm change detection logic

[Wayne Lin]

From: Wenjing Liu <wenjing.liu at amd.com>

[why]
The current ODM change detection only compares first two ODM slices.
If there are 4 ODM slices and the change is within the last two slices, the
logic fails to detect ODM change and cause us to skip ODM programming
unexpectedly.

[how]
Add a is ODM topology changed resource interface to check any ODM
topology changes with a more generic method.

Reviewed-by: Dillon Varone <dillon.varone at amd.com>
Acked-by: Wayne Lin <wayne.lin at amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu at amd.com>
---
 .../gpu/drm/amd/display/dc/core/dc_resource.c | 23 +++++++++++++++++++
 .../drm/amd/display/dc/dcn20/dcn20_hwseq.c    |  8 ++-----
 drivers/gpu/drm/amd/display/dc/inc/resource.h | 10 ++++++++
 3 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 614a1fb08809..e9837c0ce7f6 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -1925,6 +1925,29 @@ bool resource_is_pipe_topology_changed(const struct dc_state *state_a,
 	return false;
 }
 
+bool resource_is_odm_topology_changed(const struct pipe_ctx *otg_master_a,
+		const struct pipe_ctx *otg_master_b)
+{
+	const struct pipe_ctx *opp_head_a = otg_master_a;
+	const struct pipe_ctx *opp_head_b = otg_master_b;
+
+	if (!resource_is_pipe_type(otg_master_a, OTG_MASTER) ||
+			!resource_is_pipe_type(otg_master_b, OTG_MASTER))
+		return true;
+
+	while (opp_head_a && opp_head_b) {
+		if (opp_head_a->stream_res.opp != opp_head_b->stream_res.opp)
+			return true;
+		if ((opp_head_a->next_odm_pipe && !opp_head_b->next_odm_pipe) ||
+				(!opp_head_a->next_odm_pipe && opp_head_b->next_odm_pipe))
+			return true;
+		opp_head_a = opp_head_a->next_odm_pipe;
+		opp_head_b = opp_head_b->next_odm_pipe;
+	}
+
+	return false;
+}
+
 /*
  * Sample log:
  *    pipe topology update
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
index f2b20319f0bb..5738a5f00b56 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
@@ -1430,13 +1430,9 @@ static void dcn20_detect_pipe_changes(struct pipe_ctx *old_pipe, struct pipe_ctx
 	}
 
 	/* Detect top pipe only changes */
-	if (!new_pipe->top_pipe && !new_pipe->prev_odm_pipe) {
+	if (resource_is_pipe_type(new_pipe, OTG_MASTER)) {
 		/* Detect odm changes */
-		if ((old_pipe->next_odm_pipe && new_pipe->next_odm_pipe
-			&& old_pipe->next_odm_pipe->pipe_idx != new_pipe->next_odm_pipe->pipe_idx)
-				|| (!old_pipe->next_odm_pipe && new_pipe->next_odm_pipe)
-				|| (old_pipe->next_odm_pipe && !new_pipe->next_odm_pipe)
-				|| old_pipe->stream_res.opp != new_pipe->stream_res.opp)
+		if (resource_is_odm_topology_changed(new_pipe, old_pipe))
 			new_pipe->update_flags.bits.odm = 1;
 
 		/* Detect global sync changes */
diff --git a/drivers/gpu/drm/amd/display/dc/inc/resource.h b/drivers/gpu/drm/amd/display/dc/inc/resource.h
index 170d6ab81aef..00230a7fbe25 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/resource.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/resource.h
@@ -447,6 +447,16 @@ int resource_get_odm_slice_index(const struct pipe_ctx *opp_head);
 bool resource_is_pipe_topology_changed(const struct dc_state *state_a,
 		const struct dc_state *state_b);
 
+/*
+ * determine if the two OTG master pipes have the same ODM topology
+ * return
+ * false - if pipes passed in are not OTG masters or ODM topology is
+ * changed.
+ * true - otherwise
+ */
+bool resource_is_odm_topology_changed(const struct pipe_ctx *otg_master_a,
+		const struct pipe_ctx *otg_master_b);
+
 /* log the pipe topology update in state */
 void resource_log_pipe_topology_update(struct dc *dc, struct dc_state *state);
 
-- 
2.37.3