From 7b7db1b59563aebe2f4d2ba850468afb2c87c82a Mon Sep 17 00:00:00 2001 From: Stefan Bader Date: Wed, 30 Aug 2006 14:33:39 +0200 Subject: [PATCH] [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 Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/device_pgid.c | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c index 32610fd886..1693a102dc 100644 --- a/drivers/s390/cio/device_pgid.c +++ b/drivers/s390/cio/device_pgid.c @@ -23,6 +23,21 @@ #include "device.h" #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; } -- 2.39.5