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Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/cio/device_pgid.c27
1 files changed, 21 insertions, 6 deletions
diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 32610fd8868..1693a102dcf 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;
}