RDMA/mlx5: Cancel pkey work before destroying device resources

In the driver release flow, we are ensuring that notifier is disabled and
no new works can be added to pkey_change_handler. It means that we can
cancel that handler before destroying resources to make sure that our
unwind routine is symmetrical to the allocation one.

Link: https://lore.kernel.org/r/f2b1ea1bad952e4e7a48a6f731de9e0344986b29.1627040189.git.leonro@nvidia.comSigned-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/mlx5/main.c

@@ -2908,6 +2908,15 @@ static void mlx5_ib_dev_res_cleanup(struct mlx5_ib_dev *dev)
 	struct mlx5_ib_resources *devr = &dev->devr;
 	int port;
 
+	/*
+	 * Make sure no change P_Key work items are still executing.
+	 *
+	 * At this stage, the mlx5_ib_event should be unregistered
+	 * and it ensures that no new works are added.
+	 */
+	for (port = 0; port < ARRAY_SIZE(devr->ports); ++port)
+		cancel_work_sync(&devr->ports[port].pkey_change_work);
+
 	mlx5_ib_destroy_srq(devr->s1, NULL);
 	kfree(devr->s1);
 	mlx5_ib_destroy_srq(devr->s0, NULL);
@@ -2918,10 +2927,6 @@ static void mlx5_ib_dev_res_cleanup(struct mlx5_ib_dev *dev)
 	kfree(devr->c0);
 	mlx5_ib_dealloc_pd(devr->p0, NULL);
 	kfree(devr->p0);
-
-	/* Make sure no change P_Key work items are still executing */
-	for (port = 0; port < ARRAY_SIZE(devr->ports); ++port)
-		cancel_work_sync(&devr->ports[port].pkey_change_work);
 }
 
 static u32 get_core_cap_flags(struct ib_device *ibdev,