From: Dave Airlie airlied@redhat.com
If you do radeon.mst=1 on a gpu without mst hw, and then plug some mst hw it will oops instead of falling back.
So check we have DCE5 at least before proceeding.
Signed-off-by: Dave Airlie airlied@redhat.com --- drivers/gpu/drm/radeon/radeon_dp_mst.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/radeon/radeon_dp_mst.c b/drivers/gpu/drm/radeon/radeon_dp_mst.c index 2b98ed3..257b10be 100644 --- a/drivers/gpu/drm/radeon/radeon_dp_mst.c +++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c @@ -663,12 +663,17 @@ int radeon_dp_mst_probe(struct radeon_connector *radeon_connector) { struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv; + struct drm_device *dev = radeon_connector->base.dev; + struct radeon_device *rdev = dev->dev_private; int ret; u8 msg[1];
if (!radeon_mst) return 0;
+ if (!ASIC_IS_DCE5(rdev)) + return 0; + if (dig_connector->dpcd[DP_DPCD_REV] < 0x12) return 0;