lkml.org 
[lkml]   [2007]   [Nov]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch 1/4] cio: Issue SenseID per path.
From: Cornelia Huck <cornelia.huck@de.ibm.com>

We may receive a unit check for every path when we issue a SenseID.
Unfortunately, the channel subsystem will try on a different path
every time if we use a lpm of 0xff, which will exhaust our retry
counter.

Therefore, revert SenseID to its previous per-path behaviour and
just leave out the suspend multipath reconnect.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

drivers/s390/cio/device_id.c | 37 ++++++++++++++++++++++++++++---------
1 file changed, 28 insertions(+), 9 deletions(-)

Index: quilt-2.6/drivers/s390/cio/device_id.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/device_id.c
+++ quilt-2.6/drivers/s390/cio/device_id.c
@@ -113,6 +113,7 @@ __ccw_device_sense_id_start(struct ccw_d
{
struct subchannel *sch;
struct ccw1 *ccw;
+ int ret;

sch = to_subchannel(cdev->dev.parent);
/* Setup sense channel program. */
@@ -124,9 +125,25 @@ __ccw_device_sense_id_start(struct ccw_d

/* Reset device status. */
memset(&cdev->private->irb, 0, sizeof(struct irb));
- cdev->private->flags.intretry = 0;

- return cio_start(sch, ccw, LPM_ANYPATH);
+ /* Try on every path. */
+ ret = -ENODEV;
+ while (cdev->private->imask != 0) {
+ if ((sch->opm & cdev->private->imask) != 0 &&
+ cdev->private->iretry > 0) {
+ cdev->private->iretry--;
+ /* Reset internal retry indication. */
+ cdev->private->flags.intretry = 0;
+ ret = cio_start (sch, cdev->private->iccws,
+ cdev->private->imask);
+ /* ret is 0, -EBUSY, -EACCES or -ENODEV */
+ if (ret != -EACCES)
+ return ret;
+ }
+ cdev->private->imask >>= 1;
+ cdev->private->iretry = 5;
+ }
+ return ret;
}

void
@@ -136,7 +153,8 @@ ccw_device_sense_id_start(struct ccw_dev

memset (&cdev->private->senseid, 0, sizeof (struct senseid));
cdev->private->senseid.cu_type = 0xFFFF;
- cdev->private->iretry = 3;
+ cdev->private->imask = 0x80;
+ cdev->private->iretry = 5;
ret = __ccw_device_sense_id_start(cdev);
if (ret && ret != -EBUSY)
ccw_device_sense_id_done(cdev, ret);
@@ -252,13 +270,14 @@ ccw_device_sense_id_irq(struct ccw_devic
ccw_device_sense_id_done(cdev, ret);
break;
case -EACCES: /* channel is not operational. */
+ sch->lpm &= ~cdev->private->imask;
+ cdev->private->imask >>= 1;
+ cdev->private->iretry = 5;
+ /* fall through. */
case -EAGAIN: /* try again. */
- cdev->private->iretry--;
- if (cdev->private->iretry > 0) {
- ret = __ccw_device_sense_id_start(cdev);
- if (ret == 0 || ret == -EBUSY)
- break;
- }
+ ret = __ccw_device_sense_id_start(cdev);
+ if (ret == 0 || ret == -EBUSY)
+ break;
/* fall through. */
default: /* Sense ID failed. Try asking VM. */
if (MACHINE_IS_VM) {
--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-11-27 17:31    [W:0.042 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site