[S390] cio: Fix race for "fast" path gone/path back situations.

Make sure we wait for previous evaluations triggered by path state
changes to have settled before we manipulate path states again.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 3b45bbe6cce0..3e829c827493 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -533,6 +533,12 @@ void css_schedule_eval_all(void)
         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 }
 
+void css_wait_for_slow_path(void)
+{
+        flush_workqueue(ccw_device_notify_work);
+        flush_workqueue(slow_path_wq);
+}
+
 /* Reprobe subchannel if unregistered. */
 static int reprobe_subchannel(struct subchannel_id schid, void *data)
 {