drm/amd/display: Fix underflow when setting underscan on DCN401

commit f510dd5c210bf8cc22e4be48cbbda3cb754219f5 upstream.

[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@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Dillon Varone <dillon.varone@amd.com>
Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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 06387b8b0aee5e0a45f594bf2479b0bbfa1f7859..2baaf602815ec9cfa089ed29ddff25fcd4f007b1 100644 (file)
--- 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
@@ -859,7 +859,9 @@ 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.