[PATCH] drm/amd/display: fix mode scaling (RMX_.*)

[Hamza Mahfooz]

As made mention of in commit 4a2df0d1f28e ("drm/amd/display: Fixed
non-native modes not lighting up"), we shouldn't call
drm_mode_set_crtcinfo() once the crtc timings have been decided. Since,
it can cause settings to be unintentionally overwritten. So, since
dm_state is never NULL now, we can use old_stream to determine if we
should call drm_mode_set_crtcinfo() because we only need to set the crtc
timing parameters for entirely new streams.

Cc: Harry Wentland <harry.wentland@xxxxxxx>
Cc: Rodrigo Siqueira <rodrigo.siqueira@xxxxxxx>
Fixes: 712237a4a1b4 ("drm/amd/display: Always set crtcinfo from create_stream_for_sink")
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@xxxxxxx>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 3b27b7742854..e9aff5014e39 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -6035,7 +6035,7 @@ create_stream_for_sink(struct amdgpu_dm_connector *aconnector,
 
 	if (recalculate_timing)
 		drm_mode_set_crtcinfo(&saved_mode, 0);
-	else
+	else if (!old_stream)
 		drm_mode_set_crtcinfo(&mode, 0);
 
 	/*
-- 
2.41.0