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Subject[PATCH 2/3] input: hil_mlc: convert timeval to jiffies
Date
From: WEN Pingbo <pingbo.wen@linaro.org>

struct timeval is not y2038 safe, and what mlc->instart do is
scheduling a task in a fixed timeout, so jiffies is the
simplest choice here.

In hilse_donode(), the expires in mod_timer equals

jiffies + intimeout - (now - instart)

If we use jiffies in 'now', the expires equals

instart + intimeout

So, all we need to do is that making sure expires is a future
timestamp before passed it to mod_timer.

[arnd: slightly simplified patch further]

Link: https://lists.linaro.org/pipermail/y2038/2015-October/000937.html
Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/input/serio/hil_mlc.c | 18 +++++++-----------
drivers/input/serio/hp_sdc_mlc.c | 5 +----
include/linux/hil_mlc.h | 4 ++--
3 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/drivers/input/serio/hil_mlc.c b/drivers/input/serio/hil_mlc.c
index 581e47119363..e1423f7648d6 100644
--- a/drivers/input/serio/hil_mlc.c
+++ b/drivers/input/serio/hil_mlc.c
@@ -602,8 +602,8 @@ static inline void hilse_setup_input(hil_mlc *mlc, const struct hilse_node *node
BUG();
}
mlc->istarted = 1;
- mlc->intimeout = node->arg;
- do_gettimeofday(&(mlc->instart));
+ mlc->intimeout = usecs_to_jiffies(node->arg);
+ mlc->instart = jiffies;
mlc->icount = 15;
memset(mlc->ipacket, 0, 16 * sizeof(hil_packet));
BUG_ON(down_trylock(&mlc->isem));
@@ -708,7 +708,7 @@ static int hilse_donode(hil_mlc *mlc)
break;
}
mlc->ostarted = 0;
- do_gettimeofday(&(mlc->instart));
+ mlc->instart = jiffies;
write_unlock_irqrestore(&mlc->lock, flags);
nextidx = HILSEN_NEXT;
break;
@@ -729,18 +729,14 @@ static int hilse_donode(hil_mlc *mlc)
#endif

while (nextidx & HILSEN_SCHED) {
- struct timeval tv;
+ unsigned long now = jiffies;

if (!sched_long)
goto sched;

- do_gettimeofday(&tv);
- tv.tv_usec += USEC_PER_SEC * (tv.tv_sec - mlc->instart.tv_sec);
- tv.tv_usec -= mlc->instart.tv_usec;
- if (tv.tv_usec >= mlc->intimeout) goto sched;
- tv.tv_usec = (mlc->intimeout - tv.tv_usec) * HZ / USEC_PER_SEC;
- if (!tv.tv_usec) goto sched;
- mod_timer(&hil_mlcs_kicker, jiffies + tv.tv_usec);
+ if (time_after(now, mlc->instart + mlc->intimeout))
+ goto sched;
+ mod_timer(&hil_mlcs_kicker, mlc->instart + mlc->intimeout);
break;
sched:
tasklet_schedule(&hil_mlcs_tasklet);
diff --git a/drivers/input/serio/hp_sdc_mlc.c b/drivers/input/serio/hp_sdc_mlc.c
index d50f0678bf47..232d30c825bd 100644
--- a/drivers/input/serio/hp_sdc_mlc.c
+++ b/drivers/input/serio/hp_sdc_mlc.c
@@ -149,7 +149,6 @@ static int hp_sdc_mlc_in(hil_mlc *mlc, suseconds_t timeout)

/* Try to down the semaphore */
if (down_trylock(&mlc->isem)) {
- struct timeval tv;
if (priv->emtestmode) {
mlc->ipacket[0] =
HIL_ERR_INT | (mlc->opacket &
@@ -160,9 +159,7 @@ static int hp_sdc_mlc_in(hil_mlc *mlc, suseconds_t timeout)
/* printk(KERN_DEBUG PREFIX ">[%x]\n", mlc->ipacket[0]); */
goto wasup;
}
- do_gettimeofday(&tv);
- tv.tv_usec += USEC_PER_SEC * (tv.tv_sec - mlc->instart.tv_sec);
- if (tv.tv_usec - mlc->instart.tv_usec > mlc->intimeout) {
+ if (time_after(jiffies, mlc->instart + mlc->intimeout)) {
/* printk("!%i %i",
tv.tv_usec - mlc->instart.tv_usec,
mlc->intimeout);
diff --git a/include/linux/hil_mlc.h b/include/linux/hil_mlc.h
index d6fc839bdf46..774f7d3b8f6a 100644
--- a/include/linux/hil_mlc.h
+++ b/include/linux/hil_mlc.h
@@ -144,8 +144,8 @@ struct hil_mlc {
hil_packet ipacket[16];
hil_packet imatch;
int icount;
- struct timeval instart;
- suseconds_t intimeout;
+ unsigned long instart;
+ unsigned long intimeout;

int ddi; /* Last operational device id */
int lcv; /* LCV to throttle loops */
--
2.9.0
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