Merge branch 'linux-2.6'

1 files changed, 21 insertions, 6 deletions

diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 32610fd8868e..1693a102dcfe 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -24,6 +24,21 @@
 #include "ioasm.h"
 
 /*
+ * Helper function called from interrupt context to decide whether an
+ * operation should be tried again.
+ */
+static int __ccw_device_should_retry(struct scsw *scsw)
+{
+        /* CC is only valid if start function bit is set. */
+        if ((scsw->fctl & SCSW_FCTL_START_FUNC) && scsw->cc == 1)
+                return 1;
+        /* No more activity. For sense and set PGID we stubbornly try again. */
+        if (!scsw->actl)
+                return 1;
+        return 0;
+}
+
+/*
  * Start Sense Path Group ID helper function. Used in ccw_device_recog
  * and ccw_device_sense_pgid.
  */
@@ -155,10 +170,10 @@ ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
         int ret;
 
         irb = (struct irb *) __LC_IRB;
-        /* Retry sense pgid for cc=1. */
+
         if (irb->scsw.stctl ==
             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
-                if (irb->scsw.cc == 1) {
+                if (__ccw_device_should_retry(&irb->scsw)) {
                         ret = __ccw_device_sense_pgid_start(cdev);
                         if (ret && ret != -EBUSY)
                                 ccw_device_sense_pgid_done(cdev, ret);
@@ -391,10 +406,10 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
         int ret;
 
         irb = (struct irb *) __LC_IRB;
-        /* Retry set pgid for cc=1. */
+
         if (irb->scsw.stctl ==
             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
-                if (irb->scsw.cc == 1)
+                if (__ccw_device_should_retry(&irb->scsw))
                         __ccw_device_verify_start(cdev);
                 return;
         }
@@ -494,10 +509,10 @@ ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
         int ret;
 
         irb = (struct irb *) __LC_IRB;
-        /* Retry set pgid for cc=1. */
+
         if (irb->scsw.stctl ==
             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
-                if (irb->scsw.cc == 1)
+                if (__ccw_device_should_retry(&irb->scsw))
                         __ccw_device_disband_start(cdev);
                 return;
         }