| Date | Fri, 13 Nov 2009 16:08:58 +0100 | From | Martin Schwidefsky <> | Subject | [patch 34/52] [PATCH] cio: ensure proper locking during device recognition |
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From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
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(+)
Index: quilt-2.6/drivers/s390/cio/device.c =================================================================== --- quilt-2.6.orig/drivers/s390/cio/device.c 2009-11-13 16:08:18.000000000 +0100 +++ quilt-2.6/drivers/s390/cio/device.c 2009-11-13 16:08:19.000000000 +0100 @@ -488,7 +488,9 @@ { /* 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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