1 files changed, 42 insertions, 39 deletions

diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 1693a102dcfe..8ca2d078848c 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -245,18 +245,17 @@ __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
         memset(&cdev->private->irb, 0, sizeof(struct irb));
 
         /* Try multiple times. */
-        ret = -ENODEV;
+        ret = -EACCES;
         if (cdev->private->iretry > 0) {
                 cdev->private->iretry--;
                 ret = cio_start (sch, cdev->private->iccws,
                                  cdev->private->imask);
-                /* ret is 0, -EBUSY, -EACCES or -ENODEV */
-                if ((ret != -EACCES) && (ret != -ENODEV))
+                /* We expect an interrupt in case of success or busy
+                 * indication. */
+                if ((ret == 0) || (ret == -EBUSY))
                         return ret;
         }
-        /* PGID command failed on this path. Switch it off. */
-        sch->lpm &= ~cdev->private->imask;
-        sch->vpm &= ~cdev->private->imask;
+        /* PGID command failed on this path. */
         CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
                       "0.%x.%04x, lpm %02X, became 'not operational'\n",
                       cdev->private->devno, sch->schid.ssid,
@@ -286,18 +285,17 @@ static int __ccw_device_do_nop(struct ccw_device *cdev)
         memset(&cdev->private->irb, 0, sizeof(struct irb));
 
         /* Try multiple times. */
-        ret = -ENODEV;
+        ret = -EACCES;
         if (cdev->private->iretry > 0) {
                 cdev->private->iretry--;
                 ret = cio_start (sch, cdev->private->iccws,
                                  cdev->private->imask);
-                /* ret is 0, -EBUSY, -EACCES or -ENODEV */
-                if ((ret != -EACCES) && (ret != -ENODEV))
+                /* We expect an interrupt in case of success or busy
+                 * indication. */
+                if ((ret == 0) || (ret == -EBUSY))
                         return ret;
         }
-        /* nop command failed on this path. Switch it off. */
-        sch->lpm &= ~cdev->private->imask;
-        sch->vpm &= ~cdev->private->imask;
+        /* nop command failed on this path. */
         CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
                       "0.%x.%04x, lpm %02X, became 'not operational'\n",
                       cdev->private->devno, sch->schid.ssid,
@@ -372,27 +370,32 @@ static void
 __ccw_device_verify_start(struct ccw_device *cdev)
 {
         struct subchannel *sch;
-        __u8 imask, func;
+        __u8 func;
         int ret;
 
         sch = to_subchannel(cdev->dev.parent);
-        while (sch->vpm != sch->lpm) {
-                /* Find first unequal bit in vpm vs. lpm */
-                for (imask = 0x80; imask != 0; imask >>= 1)
-                        if ((sch->vpm & imask) != (sch->lpm & imask))
-                                break;
-                cdev->private->imask = imask;
+        /* Repeat for all paths. */
+        for (; cdev->private->imask; cdev->private->imask >>= 1,
+                                     cdev->private->iretry = 5) {
+                if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
+                        /* Path not available, try next. */
+                        continue;
                 if (cdev->private->options.pgroup) {
-                        func = (sch->vpm & imask) ?
-                                SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
+                        if (sch->opm & cdev->private->imask)
+                                func = SPID_FUNC_ESTABLISH;
+                        else
+                                func = SPID_FUNC_RESIGN;
                         ret = __ccw_device_do_pgid(cdev, func);
                 } else
                         ret = __ccw_device_do_nop(cdev);
+                /* We expect an interrupt in case of success or busy
+                 * indication. */
                 if (ret == 0 || ret == -EBUSY)
                         return;
-                cdev->private->iretry = 5;
+                /* Permanent path failure, try next. */
         }
-        ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
+        /* Done with all paths. */
+        ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
 }
                 
 /*
@@ -421,14 +424,14 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
         else
                 ret = __ccw_device_check_nop(cdev);
         memset(&cdev->private->irb, 0, sizeof(struct irb));
+
         switch (ret) {
         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
         case 0:
-                /* Establish or Resign Path Group done. Update vpm. */
-                if ((sch->lpm & cdev->private->imask) != 0)
-                        sch->vpm |= cdev->private->imask;
-                else
-                        sch->vpm &= ~cdev->private->imask;
+                /* Path verification ccw finished successfully, update lpm. */
+                sch->vpm |= sch->opm & cdev->private->imask;
+                /* Go on with next path. */
+                cdev->private->imask >>= 1;
                 cdev->private->iretry = 5;
                 __ccw_device_verify_start(cdev);
                 break;
@@ -441,6 +444,10 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
                         cdev->private->options.pgroup = 0;
                 else
                         cdev->private->flags.pgid_single = 1;
+                /* Retry */
+                sch->vpm = 0;
+                cdev->private->imask = 0x80;
+                cdev->private->iretry = 5;
                 /* fall through. */
         case -EAGAIN:           /* Try again. */
                 __ccw_device_verify_start(cdev);
@@ -449,8 +456,7 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
                 ccw_device_verify_done(cdev, -ETIME);
                 break;
         case -EACCES:           /* channel is not operational. */
-                sch->lpm &= ~cdev->private->imask;
-                sch->vpm &= ~cdev->private->imask;
+                cdev->private->imask >>= 1;
                 cdev->private->iretry = 5;
                 __ccw_device_verify_start(cdev);
                 break;
@@ -463,19 +469,17 @@ ccw_device_verify_start(struct ccw_device *cdev)
         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 
         cdev->private->flags.pgid_single = 0;
+        cdev->private->imask = 0x80;
         cdev->private->iretry = 5;
-        /*
-         * Update sch->lpm with current values to catch paths becoming
-         * available again.
-         */
+
+        /* Start with empty vpm. */
+        sch->vpm = 0;
+
+        /* Get current pam. */
         if (stsch(sch->schid, &sch->schib)) {
                 ccw_device_verify_done(cdev, -ENODEV);
                 return;
         }
-        sch->lpm = sch->schib.pmcw.pim &
-                sch->schib.pmcw.pam &
-                sch->schib.pmcw.pom &
-                sch->opm;
         __ccw_device_verify_start(cdev);
 }
 
@@ -524,7 +528,6 @@ ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
         switch (ret) {
         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
         case 0:                 /* disband successful. */
-                sch->vpm = 0;
                 ccw_device_disband_done(cdev, ret);
                 break;
         case -EOPNOTSUPP: