[S390] cio: Fix handling of interrupt for csch().
Wipe internal irb if the clear function bit is set before accumulating
bits from the irb in order to follow hardware behaviour.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/device_status.c b/drivers/s390/cio/device_status.c
index 25d99bd..aa96e67 100644
--- a/drivers/s390/cio/device_status.c
+++ b/drivers/s390/cio/device_status.c
@@ -221,6 +221,14 @@
cdev_irb = &cdev->private->irb;
+ /*
+ * If the clear function had been performed, all formerly pending
+ * status at the subchannel has been cleared and we must not pass
+ * intermediate accumulated status to the device driver.
+ */
+ if (irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC)
+ memset(&cdev->private->irb, 0, sizeof(struct irb));
+
/* Copy bits which are valid only for the start function. */
if (irb->scsw.fctl & SCSW_FCTL_START_FUNC) {
/* Copy key. */