[S390] cio: ensure proper locking during device recognition

Device recognition needs to be started with the ccw device lock
held to prevent race conditions between I/O starting and interrupt
reception.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 7ad6bfb2e55e20c11ded7c15fe57335970627a36..afa362ce9e856a1d56afea7787cae08f23be3988 100644 (file)
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -488,7 +488,9 @@ static int online_store_recog_and_online(struct ccw_device *cdev)
 {
        /* Do device recognition, if needed. */
        if (cdev->private->state == DEV_STATE_BOXED) {
+               spin_lock_irq(cdev->ccwlock);
                ccw_device_recognition(cdev);
+               spin_unlock_irq(cdev->ccwlock);
                wait_event(cdev->private->wait_q,
                           cdev->private->flags.recog_done);
                if (cdev->private->state != DEV_STATE_OFFLINE)