[S390] cio: Issue SenseID per path.

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>

1 files changed, 28 insertions, 9 deletions

diff --git a/drivers/s390/cio/device_id.c b/drivers/s390/cio/device_id.c
index 2f6bf462425e..156f3f9786b5 100644
--- a/drivers/s390/cio/device_id.c
+++ b/drivers/s390/cio/device_id.c
@@ -113,6 +113,7 @@ __ccw_device_sense_id_start(struct ccw_device *cdev)
 {
         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_device *cdev)
 
         /* 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_device *cdev)
 
         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_device *cdev, enum dev_event dev_event)
                 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) {