From: WEN Pingbo <pingbo....@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....@linaro.org>
Signed-off-by: Arnd Bergmann <a...@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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