From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: linux-kernel@vger.kernel.org, shbader@de.ibm.com
Subject: [S390] cio: unsolicited interrupts during sense pgid.
Date: Wed, 30 Aug 2006 14:41:43 +0200 [thread overview]
Message-ID: <20060830124143.GC22276@skybase> (raw)
From: Stefan Bader <shbader@de.ibm.com>
[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>
---
drivers/s390/cio/device_pgid.c | 27 +++++++++++++++++++++------
1 files changed, 21 insertions(+), 6 deletions(-)
diff -urpN linux-2.6/drivers/s390/cio/device_pgid.c linux-2.6-patched/drivers/s390/cio/device_pgid.c
--- linux-2.6/drivers/s390/cio/device_pgid.c 2006-08-30 14:24:13.000000000 +0200
+++ linux-2.6-patched/drivers/s390/cio/device_pgid.c 2006-08-30 14:24:35.000000000 +0200
@@ -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_dev
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
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
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;
}
reply other threads:[~2006-08-30 12:41 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20060830124143.GC22276@skybase \
--to=schwidefsky@de.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=shbader@de.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox