From 1f5bd3848bfc56de4c32ef6971a6a966776204bb Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:23 +0100
Subject: [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>
---
 drivers/s390/cio/device.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'drivers/s390/cio')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 7ad6bfb..afa362c 100644
--- 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)
-- 
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