[S390] qdio: fix qdio_activate timeout handling.

Current code in qdio_activate waits for at least 5 seconds
until it returns. It may return earlier if an error occurs,
but not if everything is ok. This large timeout value
became visible with commit dfa77f611ff295598e218aa0eb6efa73a5cf26d0
"qdio: set QDIO_ACTIVATE_TIMEOUT to 5s", which intended to
fix the timeout value which was zero. In turn setting an
FCP adapter online took 5 seconds.

In practice waiting for 5ms before continuing is sufficient
as pointed out by Utz Bacher and Cornelia Huck.

Cc: Utz Bacher <utz.bacher@de.ibm.com>
Cc: Jan Glauber <jan.glauber@de.ibm.com>
Cc: Ursula Braun <braunu@de.ibm.com>
Cc: Martin Peschke <mp3@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 3 insertions, 9 deletions

diff --git a/drivers/s390/cio/qdio.c b/drivers/s390/cio/qdio.c
index 097fc0967e9d..cd9cfc1326d2 100644
--- a/drivers/s390/cio/qdio.c
+++ b/drivers/s390/cio/qdio.c
@@ -32,7 +32,7 @@
 
 #include <linux/module.h>
 #include <linux/init.h>
-
+#include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/kernel.h>
 #include <linux/proc_fs.h>
@@ -3332,13 +3332,7 @@ qdio_activate(struct ccw_device *cdev, int flags)
                 }
         }
 
-        wait_event_interruptible_timeout(cdev->private->wait_q,
-                                         ((irq_ptr->state ==
-                                          QDIO_IRQ_STATE_STOPPED) ||
-                                          (irq_ptr->state ==
-                                           QDIO_IRQ_STATE_ERR)),
-                                         QDIO_ACTIVATE_TIMEOUT);
-
+        msleep(QDIO_ACTIVATE_TIMEOUT);
         switch (irq_ptr->state) {
         case QDIO_IRQ_STATE_STOPPED:
         case QDIO_IRQ_STATE_ERR:
diff --git a/drivers/s390/cio/qdio.h b/drivers/s390/cio/qdio.h
index 37870e4e938e..da8a272fd75b 100644
--- a/drivers/s390/cio/qdio.h
+++ b/drivers/s390/cio/qdio.h
@@ -57,10 +57,10 @@
                                             of the queue to 0 */
 
 #define QDIO_ESTABLISH_TIMEOUT (1*HZ)
-#define QDIO_ACTIVATE_TIMEOUT (5*HZ)
 #define QDIO_CLEANUP_CLEAR_TIMEOUT (20*HZ)
 #define QDIO_CLEANUP_HALT_TIMEOUT (10*HZ)
 #define QDIO_FORCE_CHECK_TIMEOUT (10*HZ)
+#define QDIO_ACTIVATE_TIMEOUT (5) /* 5 ms */
 
 enum qdio_irq_states {
         QDIO_IRQ_STATE_INACTIVE,