[PATCH] s390: re-activated path detection

If we receive path not operational indications (pnom in pmcw nonzero), we
switch off those paths.  To catch them becoming available again, we have to
recalculate the lpm from the pmcw each time we start path verification.
Signed-off-by: NCornelia Huck <cohuck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

drivers/s390/cio/device_pgid.c

@@ -22,6 +22,7 @@
 #include "cio_debug.h"
 #include "css.h"
 #include "device.h"
+#include "ioasm.h"
 
 /*
  * Start Sense Path Group ID helper function. Used in ccw_device_recog
@@ -364,8 +365,22 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
 void
 ccw_device_verify_start(struct ccw_device *cdev)
 {
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+
 	cdev->private->flags.pgid_single = 0;
 	cdev->private->iretry = 5;
+	/*
+	 * Update sch->lpm with current values to catch paths becoming
+	 * available again.
+	 */
+	if (stsch(sch->irq, &sch->schib)) {
+		ccw_device_verify_done(cdev, -ENODEV);
+		return;
+	}
+	sch->lpm = sch->schib.pmcw.pim &
+		sch->schib.pmcw.pam &
+		sch->schib.pmcw.pom &
+		sch->opm;
 	__ccw_device_verify_start(cdev);
 }