[S390] permanent subchannel busy conditions may cause I/O stall
In special conditions where a subchannel rejects the HALT I/O-
instruction with a busy indication (cc 2), I/O may stall.
I/O request termination logic retries HALT I/O indefinitely
because it expects HALT I/O to alter the subchannel status which
is not true when cc 2 is returned.
In case of a busy indication, try CLEAR I/O instruction immediately.
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_fsm.c b/drivers/s390/cio/device_fsm.c
index ac6e0c7..7a39e0b 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -152,7 +152,8 @@
if (cdev->private->iretry) {
cdev->private->iretry--;
ret = cio_halt(sch);
- return (ret == 0) ? -EBUSY : ret;
+ if (ret != -EBUSY)
+ return (ret == 0) ? -EBUSY : ret;
}
/* halt io unsuccessful. */
cdev->private->iretry = 255; /* 255 clear retries. */