From c175cd16df272119534058f28cbd5eeac6ff2d24 Mon Sep 17 00:00:00 2001 From: Andrey Grodzovsky Date: Fri, 22 Jan 2016 17:07:29 -0500 Subject: [PATCH] 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 Reviewed-by: Harry Wentland Cc: stable@vger.kernel.org Acked-by: Alex Deucher Signed-off-by: Dave Airlie --- 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 2c12a20ff08e..7e5d98c7b908 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1998,6 +1998,12 @@ 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; @@ -2005,12 +2011,6 @@ 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; -- 2.39.5