[PATCH 5.7 023/179] drm/amd/display: add dmcub check on RENOIR

[Greg Kroah-Hartman]

From: Aaron Ma <aaron.ma@xxxxxxxxxxxxx>

[ Upstream commit 3b2e973dff59d88bee1d814ddf8762a24fc02b60 ]

RENOIR loads dmub fw not dmcu, check dmcu only will prevent loading iram,
it breaks backlight control.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=208277
Acked-by: Alex Deucher <alexander.deucher@xxxxxxx>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
Signed-off-by: Aaron Ma <aaron.ma@xxxxxxxxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 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 7da2a22dbde7e..837a286469ecf 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1345,7 +1345,7 @@ static int dm_late_init(void *handle)
 	struct dmcu *dmcu = NULL;
 	bool ret;
 
-	if (!adev->dm.fw_dmcu)
+	if (!adev->dm.fw_dmcu && !adev->dm.dmub_fw)
 		return detect_mst_link_for_all_connectors(adev->ddev);
 
 	dmcu = adev->dm.dc->res_pool->dmcu;
-- 
2.25.1