svn commit: r341570 - head/sys/dev/mlx5/mlx5_ib

[Slava Shwartsman]

Author: slavash
Date: Wed Dec  5 13:48:39 2018
New Revision: 341570
URL: https://svnweb.freebsd.org/changeset/base/341570

Log:
  mlx5ib: Make sure the congestion work timer does not escape the drain procedure.
  
  If the mlx5_ib_read_cong_stats() function was running when mlx5ib was unloaded,
  because this function unconditionally restarts the timer, the timer can still
  be pending after the delayed work has been cancelled. To fix this simply loop
  on the delayed work cancel procedure as long as it returns non-zero.
  
  Submitted by:   hselasky@
  Approved by:    hselasky (mentor)
  MFC after:      1 week
  Sponsored by:   Mellanox Technologies

Modified:
  head/sys/dev/mlx5/mlx5_ib/mlx5_ib_cong.c

Modified: head/sys/dev/mlx5/mlx5_ib/mlx5_ib_cong.c
==============================================================================
--- head/sys/dev/mlx5/mlx5_ib/mlx5_ib_cong.c	Wed Dec  5 13:48:10 2018	(r341569)
+++ head/sys/dev/mlx5/mlx5_ib/mlx5_ib_cong.c	Wed Dec  5 13:48:39 2018	(r341570)
@@ -393,7 +393,8 @@ void
 mlx5_ib_cleanup_congestion(struct mlx5_ib_dev *dev)
 {
 
-	cancel_delayed_work_sync(&dev->congestion.dwork);
+	while (cancel_delayed_work_sync(&dev->congestion.dwork))
+		;
 	sysctl_ctx_free(&dev->congestion.ctx);
 	sx_destroy(&dev->congestion.lock);
 }