s390/eadm_sch: improve quiesce handling

When quiescing an eadm subchannel make sure that outstanding IO is
cleared and potential timeout handlers are canceled.

Reviewed-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/cio/eadm_sch.c b/drivers/s390/cio/eadm_sch.c
index 6b54d8a05cd437a131039a360d76032fd4ccd601..aca7bfc113aaeb4067043cd10bdc0662dd8ec286 100644 (file)
--- a/drivers/s390/cio/eadm_sch.c
+++ b/drivers/s390/cio/eadm_sch.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/kernel_stat.h>
+#include <linux/completion.h>
 #include <linux/workqueue.h>
 #include <linux/spinlock.h>
 #include <linux/device.h>
@@ -159,6 +160,9 @@ static void eadm_subchannel_irq(struct subchannel *sch)
        }
        scm_irq_handler((struct aob *)(unsigned long)scsw->aob, error);
        private->state = EADM_IDLE;
+
+       if (private->completion)
+               complete(private->completion);
 }
 
 static struct subchannel *eadm_get_idle_sch(void)
@@ -255,13 +259,32 @@ out:
 
 static void eadm_quiesce(struct subchannel *sch)
 {
+       struct eadm_private *private = get_eadm_private(sch);
+       DECLARE_COMPLETION_ONSTACK(completion);
        int ret;
 
+       spin_lock_irq(sch->lock);
+       if (private->state != EADM_BUSY)
+               goto disable;
+
+       if (eadm_subchannel_clear(sch))
+               goto disable;
+
+       private->completion = &completion;
+       spin_unlock_irq(sch->lock);
+
+       wait_for_completion_io(&completion);
+
+       spin_lock_irq(sch->lock);
+       private->completion = NULL;
+
+disable:
+       eadm_subchannel_set_timeout(sch, 0);
        do {
-               spin_lock_irq(sch->lock);
                ret = cio_disable_subchannel(sch);
-               spin_unlock_irq(sch->lock);
        } while (ret == -EBUSY);
+
+       spin_unlock_irq(sch->lock);
 }
 
 static int eadm_subchannel_remove(struct subchannel *sch)

diff --git a/drivers/s390/cio/eadm_sch.h b/drivers/s390/cio/eadm_sch.h
index 2779be093982ee1c219f4c9c6c24ab8edebe8ce3..9664e4653f9861416a78f4193cbe57d8d3105864 100644 (file)
--- a/drivers/s390/cio/eadm_sch.h
+++ b/drivers/s390/cio/eadm_sch.h
@@ -1,6 +1,7 @@
 #ifndef EADM_SCH_H
 #define EADM_SCH_H
 
+#include <linux/completion.h>
 #include <linux/device.h>
 #include <linux/timer.h>
 #include <linux/list.h>
@@ -9,9 +10,10 @@
 struct eadm_private {
        union orb orb;
        enum {EADM_IDLE, EADM_BUSY, EADM_NOT_OPER} state;
+       struct completion *completion;
+       struct subchannel *sch;
        struct timer_list timer;
        struct list_head head;
-       struct subchannel *sch;
 } __aligned(8);
 
 #define get_eadm_private(n) ((struct eadm_private *)dev_get_drvdata(&n->dev))