[PATCH] drm/mst: drop cancel work sync in the mstb destroy path

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

Since 9eb1e57f564d4e6e10991402726cc83fe0b9172f
drm/dp/mst: make sure mst_primary mstb is valid in work function

we validate the mstb structs in the work function, and doing
that takes a reference. So we should never get here with the
work function running using the mstb device, only if the work
function hasn't run yet or is running for another mstb.

So we don't need to sync the work here, this was causing
lockdep spew when the device failed during the initial EDID
read.

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 drivers/gpu/drm/drm_dp_mst_topology.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index e23df5f..16f911c 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -804,8 +804,6 @@ static void drm_dp_destroy_mst_branch_device(struct kref *kref)
 	struct drm_dp_mst_port *port, *tmp;
 	bool wake_tx = false;
 
-	cancel_work_sync(&mstb->mgr->work);
-
 	/*
 	 * destroy all ports - don't need lock
 	 * as there are no more references to the mst branch
-- 
2.4.3