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[S390] qdio: fix qdio_activate timeout handling.
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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 dfa77f6
"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>
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Heiko Carstens authored and Martin Schwidefsky committed Feb 19, 2008
1 parent 591bb4f commit b32ecdb
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Showing 2 changed files with 3 additions and 9 deletions.
10 changes: 2 additions & 8 deletions drivers/s390/cio/qdio.c
Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -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:
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2 changes: 1 addition & 1 deletion drivers/s390/cio/qdio.h
Original file line number Diff line number Diff line change
Expand Up @@ -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,
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