3.19.8-ckt16 -stable review patch. If anyone has any objections, please let me
know.
---8<------------------------------------------------------------
From: Andrey Grodzovsky <andrey.grodzov...@amd.com>
commit c175cd16df272119534058f28cbd5eeac6ff2d24 upstream.
On DELL U3014 if you clear the table before enabling MST it sometimes
hangs the receiver.
Signed-off-by: Andrey Grodzovsky <andrey.grodzov...@amd.com>
Reviewed-by: Harry Wentland <harry.wentl...@amd.com>
Acked-by: Alex Deucher <alexander.deuc...@amd.com>
Signed-off-by: Dave Airlie <airl...@redhat.com>
Signed-off-by: Kamal Mostafa <ka...@canonical.com>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
b/drivers/gpu/drm/drm_dp_mst_topology.c
index 60e7ac6..45b2f76 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1964,6 +1964,12 @@ int drm_dp_mst_topology_mgr_set_mst(struct
drm_dp_mst_topology_mgr *mgr, bool ms
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;
@@ -1971,12 +1977,6 @@ int drm_dp_mst_topology_mgr_set_mst(struct
drm_dp_mst_topology_mgr *mgr, bool ms
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;
- }
-
/* sort out guid */
ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
--
2.7.0
