[S390] cio: Avoid machine check vs. not operational races.

There was the possibilty that an action like ccw_device_set_offline()
triggered by a device gone machine check might trigger a not oper
event. Unfortunately, this could lead to the situation that we tried
to unregister a subchannel twice: Once from the slow path evaluation,
and once via the not oper event.

Fix this by always using the same mechanism (css_schedule_eval()) for
triggering the unregister. This makes sure that unregistration will
only be done once. As an added bonus, it also simplyfies the code.

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

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index c96380db0136..39f02b48e4c7 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -969,8 +969,7 @@ out:
                 wake_up(&ccw_device_init_wq);
 }
 
-void
-ccw_device_call_sch_unregister(struct work_struct *work)
+static void ccw_device_call_sch_unregister(struct work_struct *work)
 {
         struct ccw_device_private *priv;
         struct ccw_device *cdev;