drm/dp/mst: Reverse order of MST enable and clearing VC payload table.
On DELL U3014 if you clear the table before enabling MST it sometimes
hangs the receiver.
Signed-off-by: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Cc: stable@vger.kernel.org
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 2c12a20..7e5d98c 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1998,6 +1998,12 @@
mgr->mst_primary = mstb;
kref_get(&mgr->mst_primary->kref);
+ ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
+ DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
+ if (ret < 0) {
+ goto out_unlock;
+ }
+
{
struct drm_dp_payload reset_pay;
reset_pay.start_slot = 0;
@@ -2005,12 +2011,6 @@
drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
}
- ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
- DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
- if (ret < 0) {
- goto out_unlock;
- }
-
queue_work(system_long_wq, &mgr->work);
ret = 0;
