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authorSebastian Ott <sebott@linux.vnet.ibm.com>2012-09-05 14:19:42 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-09-06 10:40:39 +0200
commit43d0be75af8d05654b88d1da494cf292714fbdec (patch)
treee95e17c270b88565bc3d91a5d4ac6abf7127399d
parent1f08be80bef6f7a3faaa728db836b47ff742f41f (diff)
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s390/cio: fix IO subchannel event race
If the subchannel event function is called from IRQ context and we observe that the subchannel in question is gone we flag the attached device as not operational and schedule the event function to be called again from process context where the subchannel gets deregistered. However if the subchannel reappeared at the time the event function gets called from process context we would do nothing and leave the device in not operational state. Recognize this case in sch_get_action and trigger reexamination of the subchannel/device. Acked-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--drivers/s390/cio/device.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index ed25c8740a9..e8e1a108cdf 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1426,6 +1426,8 @@ static enum io_sch_action sch_get_action(struct subchannel *sch)
return IO_SCH_REPROBE;
if (cdev->online)
return IO_SCH_VERIFY;
+ if (cdev->private->state == DEV_STATE_NOT_OPER)
+ return IO_SCH_UNREG_ATTACH;
return IO_SCH_NOP;
}