X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fs390%2Fcio%2Fdevice_status.c;h=aa96e6752592355a06b5a4fb6c97f346e4c1066d;hb=b5faa4b89e4d83203b1f44f143a351b518f7cda2;hp=6b1caea622ea8a1b3ee416477d8de1514ab99fa7;hpb=4d284cac76d0bfebc42d76b428c4e44d921200a9;p=linux-2.6

diff --git a/drivers/s390/cio/device_status.c b/drivers/s390/cio/device_status.c
index 6b1caea622..aa96e67525 100644
--- a/drivers/s390/cio/device_status.c
+++ b/drivers/s390/cio/device_status.c
@@ -221,6 +221,14 @@ ccw_device_accumulate_irb(struct ccw_device *cdev, struct irb *irb)
 
 	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. */
@@ -263,7 +271,11 @@ ccw_device_accumulate_irb(struct ccw_device *cdev, struct irb *irb)
 		cdev_irb->scsw.cpa = irb->scsw.cpa;
 	/* Accumulate device status, but not the device busy flag. */
 	cdev_irb->scsw.dstat &= ~DEV_STAT_BUSY;
-	cdev_irb->scsw.dstat |= irb->scsw.dstat;
+	/* dstat is not always valid. */
+	if (irb->scsw.stctl &
+	    (SCSW_STCTL_PRIM_STATUS | SCSW_STCTL_SEC_STATUS
+	     | SCSW_STCTL_INTER_STATUS | SCSW_STCTL_ALERT_STATUS))
+		cdev_irb->scsw.dstat |= irb->scsw.dstat;
 	/* Accumulate subchannel status. */
 	cdev_irb->scsw.cstat |= irb->scsw.cstat;
 	/* Copy residual count if it is valid. */