[PATCH 18/23] drm/amd/display: Fix underflow when setting underscan on DCN401

[Alex Hung]

From: Aurabindo Pillai <aurabindo.pillai at amd.com>

[WHY & HOW]
When underscan is set through xrandr, it causes the stream destination
rect to change in a way it becomes complicated to handle the calculations
for subvp. Since this is a corner case, disable subvp when underscan is
set.

Fix the existing check that is supposed to catch this corner case by
adding a check based on the parameters in the stream

Cc: Mario Limonciello <mario.limonciello at amd.com>
Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: stable at vger.kernel.org
Reviewed-by: Dillon Varone <dillon.varone at amd.com>
Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira at amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai at amd.com>
Signed-off-by: Alex Hung <alex.hung at amd.com>
---
 .../drm/amd/display/dc/dml2/dml21/dml21_translation_helper.c  | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_translation_helper.c b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_translation_helper.c
index b0d9aed0f265..8697eac1e1f7 100644
--- a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_translation_helper.c
+++ b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_translation_helper.c
@@ -858,7 +858,9 @@ static void populate_dml21_plane_config_from_plane_state(struct dml2_context *dm
 
 	plane->immediate_flip = plane_state->flip_immediate;
 
-	plane->composition.rect_out_height_spans_vactive = plane_state->dst_rect.height >= stream->timing.v_addressable;
+	plane->composition.rect_out_height_spans_vactive =
+		plane_state->dst_rect.height >= stream->timing.v_addressable &&
+		stream->dst.height >= stream->timing.v_addressable;
 }
 
 //TODO : Could be possibly moved to a common helper layer.
-- 
2.34.1