2022-03-22 03:21:42

by Yu Liao

Subject: [PATCH] s390: cleanup timer API use

cleanup the s390's use of the timer API
- del_timer() contains timer_pending() condition
- mod_timer(timer, expires) is equivalent to:

del_timer(timer);
timer->expires = expires;
add_timer(timer);

If the timer is inactive it will be activated, using add_timer() on
condition !timer_pending(&private->timer) is redundant.

Just cleanup, no logic change.

Signed-off-by: Yu Liao <[email protected]>
---
drivers/s390/char/sclp.c | 4 +---
drivers/s390/char/sclp_con.c | 3 +--
drivers/s390/char/sclp_vt220.c | 6 ++----
drivers/s390/cio/device_fsm.c | 12 +++---------
drivers/s390/cio/eadm_sch.c | 12 +++---------
5 files changed, 10 insertions(+), 27 deletions(-)

diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index f0763e36b861..cb2491761958 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -745,9 +745,7 @@ sclp_sync_wait(void)
/* Loop until driver state indicates finished request */
while (sclp_running_state != sclp_running_state_idle) {
/* Check for expired request timer */
- if (timer_pending(&sclp_request_timer) &&
- get_tod_clock_fast() > timeout &&
- del_timer(&sclp_request_timer))
+ if (get_tod_clock_fast() > timeout && del_timer(&sclp_request_timer))
sclp_request_timer.function(&sclp_request_timer);
cpu_relax();
}
diff --git a/drivers/s390/char/sclp_con.c b/drivers/s390/char/sclp_con.c
index de028868c6f4..fe5ee2646fcf 100644
--- a/drivers/s390/char/sclp_con.c
+++ b/drivers/s390/char/sclp_con.c
@@ -109,8 +109,7 @@ static void sclp_console_sync_queue(void)
unsigned long flags;

spin_lock_irqsave(&sclp_con_lock, flags);
- if (timer_pending(&sclp_con_timer))
- del_timer(&sclp_con_timer);
+ del_timer(&sclp_con_timer);
while (sclp_con_queue_running) {
spin_unlock_irqrestore(&sclp_con_lock, flags);
sclp_sync_wait();
diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
index 7bc4e4a10937..3b4e7e5d9b71 100644
--- a/drivers/s390/char/sclp_vt220.c
+++ b/drivers/s390/char/sclp_vt220.c
@@ -231,8 +231,7 @@ sclp_vt220_emit_current(void)
list_add_tail(&sclp_vt220_current_request->list,
&sclp_vt220_outqueue);
sclp_vt220_current_request = NULL;
- if (timer_pending(&sclp_vt220_timer))
- del_timer(&sclp_vt220_timer);
+ del_timer(&sclp_vt220_timer);
}
sclp_vt220_flush_later = 0;
}
@@ -776,8 +775,7 @@ static void __sclp_vt220_flush_buffer(void)

sclp_vt220_emit_current();
spin_lock_irqsave(&sclp_vt220_lock, flags);
- if (timer_pending(&sclp_vt220_timer))
- del_timer(&sclp_vt220_timer);
+ del_timer(&sclp_vt220_timer);
while (sclp_vt220_queue_running) {
spin_unlock_irqrestore(&sclp_vt220_lock, flags);
sclp_sync_wait();
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index 05e136cfb8be..6d63b968309a 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -113,16 +113,10 @@ ccw_device_timeout(struct timer_list *t)
void
ccw_device_set_timeout(struct ccw_device *cdev, int expires)
{
- if (expires == 0) {
+ if (expires == 0)
del_timer(&cdev->private->timer);
- return;
- }
- if (timer_pending(&cdev->private->timer)) {
- if (mod_timer(&cdev->private->timer, jiffies + expires))
- return;
- }
- cdev->private->timer.expires = jiffies + expires;
- add_timer(&cdev->private->timer);
+ else
+ mod_timer(&cdev->private->timer, jiffies + expires);
}

int
diff --git a/drivers/s390/cio/eadm_sch.c b/drivers/s390/cio/eadm_sch.c
index 8b463681a149..ab6a7495180a 100644
--- a/drivers/s390/cio/eadm_sch.c
+++ b/drivers/s390/cio/eadm_sch.c
@@ -112,16 +112,10 @@ static void eadm_subchannel_set_timeout(struct subchannel *sch, int expires)
{
struct eadm_private *private = get_eadm_private(sch);

- if (expires == 0) {
+ if (expires == 0)
del_timer(&private->timer);
- return;
- }
- if (timer_pending(&private->timer)) {
- if (mod_timer(&private->timer, jiffies + expires))
- return;
- }
- private->timer.expires = jiffies + expires;
- add_timer(&private->timer);
+ else
+ mod_timer(&private->timer, jiffies + expires);
}

static void eadm_subchannel_irq(struct subchannel *sch)
--
2.25.1

2022-03-25 18:58:18

by Heiko Carstens

Subject: Re: [PATCH] s390: cleanup timer API use

On Tue, Mar 22, 2022 at 11:00:57AM +0800, Yu Liao wrote:
> cleanup the s390's use of the timer API
> - del_timer() contains timer_pending() condition
> - mod_timer(timer, expires) is equivalent to:
>
> del_timer(timer);
> timer->expires = expires;
> add_timer(timer);
>
> If the timer is inactive it will be activated, using add_timer() on
> condition !timer_pending(&private->timer) is redundant.
>
> Just cleanup, no logic change.
>
> Signed-off-by: Yu Liao <[email protected]>
> ---
> drivers/s390/char/sclp.c | 4 +---
> drivers/s390/char/sclp_con.c | 3 +--
> drivers/s390/char/sclp_vt220.c | 6 ++----
> drivers/s390/cio/device_fsm.c | 12 +++---------
> drivers/s390/cio/eadm_sch.c | 12 +++---------
> 5 files changed, 10 insertions(+), 27 deletions(-)

Applied, thanks.