Atm, a pending delayed destroy work during module removal will be
canceled, leaving behind MST ports, mstbs. Fix this by using a dedicated
workqueue which will be drained of requeued items as well when
destroying it.
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 17 ++++++++++++++---
include/drm/drm_dp_mst_helper.h | 8 ++++++++
2 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 083255c33ee0..075fb5ac9264 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1630,7 +1630,7 @@ static void drm_dp_destroy_mst_branch_device(struct kref *kref)
mutex_lock(&mgr->delayed_destroy_lock);
list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
mutex_unlock(&mgr->delayed_destroy_lock);
- schedule_work(&mgr->delayed_destroy_work);
+ queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
}
/**
@@ -1747,7 +1747,7 @@ static void drm_dp_destroy_port(struct kref *kref)
mutex_lock(&mgr->delayed_destroy_lock);
list_add(&port->next, &mgr->destroy_port_list);
mutex_unlock(&mgr->delayed_destroy_lock);
- schedule_work(&mgr->delayed_destroy_work);
+ queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
}
/**
@@ -5208,6 +5208,15 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
INIT_LIST_HEAD(&mgr->destroy_port_list);
INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
INIT_LIST_HEAD(&mgr->up_req_list);
+
+ /*
+ * delayed_destroy_work will be queued on a dedicated WQ, so that any
+ * requeuing will be also flushed when deiniting the topology manager.
+ */
+ mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0);
+ if (mgr->delayed_destroy_wq == NULL)
+ return -ENOMEM;
+
INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
@@ -5252,7 +5261,9 @@ void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
{
drm_dp_mst_topology_mgr_set_mst(mgr, false);
flush_work(&mgr->work);
- cancel_work_sync(&mgr->delayed_destroy_work);
+ /* The following will also drain any requeued work on the WQ. */
+ destroy_workqueue(mgr->delayed_destroy_wq);
+ mgr->delayed_destroy_wq = NULL;
mutex_lock(&mgr->payload_lock);
kfree(mgr->payloads);
mgr->payloads = NULL;
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
index b230ff6f7081..8b9eb4db3381 100644
--- a/include/drm/drm_dp_mst_helper.h
+++ b/include/drm/drm_dp_mst_helper.h
@@ -681,6 +681,14 @@ struct drm_dp_mst_topology_mgr {
* @destroy_branch_device_list.
*/
struct mutex delayed_destroy_lock;
+
+ /**
+ * @delayed_destroy_wq: Workqueue used for delayed_destroy_work items.
+ * A dedicated WQ makes it possible to drain any requeued work items
+ * on it.
+ */
+ struct workqueue_struct *delayed_destroy_wq;
+
/**
* @delayed_destroy_work: Work item to destroy MST port and branch
* devices, needed to avoid locking inversion.
--
2.23.1
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