[added to the 3.18 stable tree] drm/dp/mst: Reverse order of MST enable and clearing VC payload table.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Andrey Grodzovsky <Andrey.Grodzovsky@xxxxxxx>

This patch has been added to the 3.18 stable tree. If you have any
objections, please let us know.

===============

[ Upstream commit c175cd16df272119534058f28cbd5eeac6ff2d24 ]

On DELL U3014 if you clear the table before enabling MST it sometimes
hangs the receiver.

Signed-off-by: Andrey Grodzovsky <Andrey.Grodzovsky@xxxxxxx>
Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
 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 4e781f0..563d3d2 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1933,6 +1933,12 @@ 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;
@@ -1940,12 +1946,6 @@ 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;
-		}
-
 		queue_work(system_long_wq, &mgr->work);
 
 		ret = 0;
-- 
2.5.0

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]