From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
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@xxxxxxxxxx>
Cc: Jan Glauber <jan.glauber@xxxxxxxxxx>
Cc: Ursula Braun <braunu@xxxxxxxxxx>
Cc: Martin Peschke <mp3@xxxxxxxxxx>
Acked-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---
drivers/s390/cio/qdio.c | 10 ++--------
drivers/s390/cio/qdio.h | 2 +-
2 files changed, 3 insertions(+), 9 deletions(-)
Index: quilt-2.6/drivers/s390/cio/qdio.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/qdio.c
+++ quilt-2.6/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, i
}
}
- 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:
Index: quilt-2.6/drivers/s390/cio/qdio.h
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/qdio.h
+++ quilt-2.6/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,
--
blue skies,
Martin.
"Reality continues to ruin my life." - Calvin.
-
To unsubscribe from this list: send the line "unsubscribe linux-s390" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
