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authorStefan Bader <shbader@de.ibm.com>2006-08-30 14:33:39 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2006-08-30 14:33:39 +0200
commit7b7db1b59563aebe2f4d2ba850468afb2c87c82a (patch)
tree13906695f3afecc6329a2859fd8cdc54af099946 /drivers/s390/cio
parent3b88508a31a77eb3487154922e1eff282dc1d863 (diff)
[S390] cio: unsolicited interrupts during sense pgid.
Calls to set a device online with path grouping may get stuck in some cases because certain device conditions where discarded after unsolicited interrupts. Check subchannel activity after unsolicited interrupts and retry the operation if the subchannel is idle. Signed-off-by: Stefan Bader <shbader@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/cio')
-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;
}