| Message ID | 20200610134704.25270-1-imre.deak@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
my crunch time is over so I can review these on time now :) one small comment below, although it doesn't stop me from giving my R-B here: Reviewed-by: Lyude Paul <lyude@redhat.com> On Wed, 2020-06-10 at 16:47 +0300, Imre Deak wrote: > 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. > > v2: > - Check if wq is NULL before calling destroy_workqueue(). > > Cc: Lyude Paul <lyude@redhat.com> > Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> > Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> > Signed-off-by: Imre Deak <imre.deak@intel.com> > --- > drivers/gpu/drm/drm_dp_mst_topology.c | 19 ++++++++++++++++--- > include/drm/drm_dp_mst_helper.h | 8 ++++++++ > 2 files changed, 24 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c > b/drivers/gpu/drm/drm_dp_mst_topology.c > index eff8d6ac0273..a5f67b9db7fa 100644 > --- a/drivers/gpu/drm/drm_dp_mst_topology.c > +++ b/drivers/gpu/drm/drm_dp_mst_topology.c > @@ -1604,7 +1604,7 @@ 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); > } > > /** > @@ -1721,7 +1721,7 @@ 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); > } > > /** > @@ -5182,6 +5182,15 @@ 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); > @@ -5226,7 +5235,11 @@ 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. */ > + if (mgr->delayed_destroy_wq) { > + destroy_workqueue(mgr->delayed_destroy_wq); > + mgr->delayed_destroy_wq = NULL; > + } We should definitely cleanup the cleanup in this function, I don't mind submitting some patches to do it today if you poke me on IRC once you've got this pushed to drm-misc-next > 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 9e1ffcd7cb68..17b568c6f4f8 100644 > --- a/include/drm/drm_dp_mst_helper.h > +++ b/include/drm/drm_dp_mst_helper.h > @@ -672,6 +672,14 @@ 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.
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index eff8d6ac0273..a5f67b9db7fa 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1604,7 +1604,7 @@ 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); } /** @@ -1721,7 +1721,7 @@ 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); } /** @@ -5182,6 +5182,15 @@ 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); @@ -5226,7 +5235,11 @@ 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. */ + if (mgr->delayed_destroy_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 9e1ffcd7cb68..17b568c6f4f8 100644 --- a/include/drm/drm_dp_mst_helper.h +++ b/include/drm/drm_dp_mst_helper.h @@ -672,6 +672,14 @@ 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.