[PATCH V2] hil_mlc: convert timeval to ktime_t

From: WEN Pingbo
Date: Fri Oct 23 2015 - 05:25:26 EST


Using struct timeval will cause time overflow in 2038, replacing it with
ktime_t. And we don't need to handle sec and nsec separately.

Since mlc->lcv_t is only interested in seconds, directly using
time64_t here.

And monotonic time is better here, since the original driver don't care
the wall time.

In addition, the original driver try to covert usec to jiffies manually in
hilse_donode(). This is not a universal and safe way, using
nsecs_to_jiffies() to fix that.

Signed-off-by: WEN Pingbo <pingbo.wen@xxxxxxxxxx>
---
drivers/input/serio/hil_mlc.c | 28 +++++++++++++---------------
drivers/input/serio/hp_sdc_mlc.c | 8 ++++----
include/linux/hil_mlc.h | 4 ++--
3 files changed, 19 insertions(+), 21 deletions(-)

diff --git a/drivers/input/serio/hil_mlc.c b/drivers/input/serio/hil_mlc.c
index 65605e4..2746509 100644
--- a/drivers/input/serio/hil_mlc.c
+++ b/drivers/input/serio/hil_mlc.c
@@ -274,14 +274,12 @@ static int hilse_match(hil_mlc *mlc, int unused)
/* An LCV used to prevent runaway loops, forces 5 second sleep when reset. */
static int hilse_init_lcv(hil_mlc *mlc, int unused)
{
- struct timeval tv;
+ time64_t now = ktime_get_seconds();

- do_gettimeofday(&tv);
-
- if (mlc->lcv && (tv.tv_sec - mlc->lcv_tv.tv_sec) < 5)
+ if (mlc->lcv && (now - mlc->lcv_t) < 5)
return -1;

- mlc->lcv_tv = tv;
+ mlc->lcv_t = now;
mlc->lcv = 0;

return 0;
@@ -605,7 +603,7 @@ static inline void hilse_setup_input(hil_mlc *mlc, const struct hilse_node *node
}
mlc->istarted = 1;
mlc->intimeout = node->arg;
- do_gettimeofday(&(mlc->instart));
+ mlc->instart = ktime_get();
mlc->icount = 15;
memset(mlc->ipacket, 0, 16 * sizeof(hil_packet));
BUG_ON(down_trylock(&mlc->isem));
@@ -710,7 +708,7 @@ static int hilse_donode(hil_mlc *mlc)
break;
}
mlc->ostarted = 0;
- do_gettimeofday(&(mlc->instart));
+ mlc->instart = ktime_get();
write_unlock_irqrestore(&mlc->lock, flags);
nextidx = HILSEN_NEXT;
break;
@@ -731,18 +729,18 @@ static int hilse_donode(hil_mlc *mlc)
#endif

while (nextidx & HILSEN_SCHED) {
- struct timeval tv;
+ ktime_t tmp = ktime_sub(ktime_get(), mlc->instart);

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 (tmp.tv64 >= (mlc->intimeout * NSEC_PER_USEC))
+ goto sched;
+ tmp.tv64 = mlc->intimeout * NSEC_PER_USEC - tmp.tv64;
+ if (tmp.tv64 < NSEC_PER_USEC)
+ goto sched;
+ mod_timer(&hil_mlcs_kicker,
+ jiffies + nsecs_to_jiffies(tmp.tv64));
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 d50f067..0a27b89 100644
--- a/drivers/input/serio/hp_sdc_mlc.c
+++ b/drivers/input/serio/hp_sdc_mlc.c
@@ -149,7 +149,8 @@ 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;
+ ktime_t tmp = ktime_sub(ktime_get(), mlc->instart);
+
if (priv->emtestmode) {
mlc->ipacket[0] =
HIL_ERR_INT | (mlc->opacket &
@@ -160,9 +161,8 @@ 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 (tmp.tv64 > mlc->intimeout * NSEC_PER_USEC) {
/* 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 394a840..2222ec6 100644
--- a/include/linux/hil_mlc.h
+++ b/include/linux/hil_mlc.h
@@ -144,12 +144,12 @@ struct hil_mlc {
hil_packet ipacket[16];
hil_packet imatch;
int icount;
- struct timeval instart;
+ ktime_t instart;
suseconds_t intimeout;

int ddi; /* Last operational device id */
int lcv; /* LCV to throttle loops */
- struct timeval lcv_tv; /* Time loop was started */
+ time64_t lcv_t; /* Time loop was started */

int di_map[7]; /* Maps below items to live devs */
struct hil_mlc_devinfo di[HIL_MLC_DEVMEM];
--
1.9.1

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