[S390] cio: always query all paths on path verification.

Reappearing channel paths are sometimes not utilized by CCW devices
because path verification incorrectly relies on path-operational-mask
information which is not updated until a channel path has been used
again.
Modify path verification procedure to always query all available paths
to a device.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 23 insertions, 16 deletions

diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index 7756f324fb6f..dace46fc32e8 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -232,10 +232,7 @@ ccw_device_recog_done(struct ccw_device *cdev, int state)
          */
         old_lpm = sch->lpm;
         stsch(sch->schid, &sch->schib);
-        sch->lpm = sch->schib.pmcw.pim &
-                sch->schib.pmcw.pam &
-                sch->schib.pmcw.pom &
-                sch->opm;
+        sch->lpm = sch->schib.pmcw.pam & sch->opm;
         /* Check since device may again have become not operational. */
         if (!sch->schib.pmcw.dnv)
                 state = DEV_STATE_NOT_OPER;
@@ -455,8 +452,8 @@ ccw_device_sense_pgid_done(struct ccw_device *cdev, int err)
                 return;
         }
         /* Start Path Group verification. */
-        sch->vpm = 0;   /* Start with no path groups set. */
         cdev->private->state = DEV_STATE_VERIFY;
+        cdev->private->flags.doverify = 0;
         ccw_device_verify_start(cdev);
 }
 
@@ -556,7 +553,19 @@ ccw_device_nopath_notify(void *data)
 void
 ccw_device_verify_done(struct ccw_device *cdev, int err)
 {
-        cdev->private->flags.doverify = 0;
+        struct subchannel *sch;
+
+        sch = to_subchannel(cdev->dev.parent);
+        /* Update schib - pom may have changed. */
+        stsch(sch->schid, &sch->schib);
+        /* Update lpm with verified path mask. */
+        sch->lpm = sch->vpm;
+        /* Repeat path verification? */
+        if (cdev->private->flags.doverify) {
+                cdev->private->flags.doverify = 0;
+                ccw_device_verify_start(cdev);
+                return;
+        }
         switch (err) {
         case -EOPNOTSUPP: /* path grouping not supported, just set online. */
                 cdev->private->options.pgroup = 0;
@@ -614,6 +623,7 @@ ccw_device_online(struct ccw_device *cdev)
         if (!cdev->private->options.pgroup) {
                 /* Start initial path verification. */
                 cdev->private->state = DEV_STATE_VERIFY;
+                cdev->private->flags.doverify = 0;
                 ccw_device_verify_start(cdev);
                 return 0;
         }
@@ -660,7 +670,6 @@ ccw_device_offline(struct ccw_device *cdev)
         /* Are we doing path grouping? */
         if (!cdev->private->options.pgroup) {
                 /* No, set state offline immediately. */
-                sch->vpm = 0;
                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
                 return 0;
         }
@@ -781,6 +790,7 @@ ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
         }
         /* Device is idle, we can do the path verification. */
         cdev->private->state = DEV_STATE_VERIFY;
+        cdev->private->flags.doverify = 0;
         ccw_device_verify_start(cdev);
 }
 
@@ -1043,9 +1053,9 @@ ccw_device_wait4io_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 }
 
 static void
-ccw_device_wait4io_verify(struct ccw_device *cdev, enum dev_event dev_event)
+ccw_device_delay_verify(struct ccw_device *cdev, enum dev_event dev_event)
 {
-        /* When the I/O has terminated, we have to start verification. */
+        /* Start verification after current task finished. */
         cdev->private->flags.doverify = 1;
 }
 
@@ -1111,10 +1121,7 @@ device_trigger_reprobe(struct subchannel *sch)
          * The pim, pam, pom values may not be accurate, but they are the best
          * we have before performing device selection :/
          */
-        sch->lpm = sch->schib.pmcw.pim &
-                sch->schib.pmcw.pam &
-                sch->schib.pmcw.pom &
-                sch->opm;
+        sch->lpm = sch->schib.pmcw.pam & sch->opm;
         /* Re-set some bits in the pmcw that were lost. */
         sch->schib.pmcw.isc = 3;
         sch->schib.pmcw.csense = 1;
@@ -1238,7 +1245,7 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
                 [DEV_EVENT_INTERRUPT]   = ccw_device_verify_irq,
                 [DEV_EVENT_TIMEOUT]     = ccw_device_onoff_timeout,
-                [DEV_EVENT_VERIFY]      = ccw_device_nop,
+                [DEV_EVENT_VERIFY]      = ccw_device_delay_verify,
         },
         [DEV_STATE_ONLINE] = {
                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
@@ -1281,7 +1288,7 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
                 [DEV_EVENT_INTERRUPT]   = ccw_device_wait4io_irq,
                 [DEV_EVENT_TIMEOUT]     = ccw_device_wait4io_timeout,
-                [DEV_EVENT_VERIFY]      = ccw_device_wait4io_verify,
+                [DEV_EVENT_VERIFY]      = ccw_device_delay_verify,
         },
         [DEV_STATE_QUIESCE] = {
                 [DEV_EVENT_NOTOPER]     = ccw_device_quiesce_done,
@@ -1294,7 +1301,7 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
                 [DEV_EVENT_NOTOPER]     = ccw_device_nop,
                 [DEV_EVENT_INTERRUPT]   = ccw_device_start_id,
                 [DEV_EVENT_TIMEOUT]     = ccw_device_bug,
-                [DEV_EVENT_VERIFY]      = ccw_device_nop,
+                [DEV_EVENT_VERIFY]      = ccw_device_start_id,
         },
         [DEV_STATE_DISCONNECTED_SENSE_ID] = {
                 [DEV_EVENT_NOTOPER]     = ccw_device_recog_notoper,