clocksource: sh_cmt: One-off clockevent fix V2

Fix a one-off error in the CMT driver V2. The match register
should be programmed with the period minus one.

Many thanks to Eiraku-san for tracking down this issue.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
index 717305d30444..ed8e07b97e27 100644
--- a/drivers/clocksource/sh_cmt.c
+++ b/drivers/clocksource/sh_cmt.c
@@ -308,7 +308,7 @@ static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id)
          * isr before we end up here.
          */
         if (p->flags & FLAG_CLOCKSOURCE)
-                p->total_cycles += p->match_value;
+                p->total_cycles += p->match_value + 1;
 
         if (!(p->flags & FLAG_REPROGRAM))
                 p->next_match_value = p->max_match_value;
@@ -403,7 +403,7 @@ static cycle_t sh_cmt_clocksource_read(struct clocksource *cs)
         raw = sh_cmt_get_counter(p, &has_wrapped);
 
         if (unlikely(has_wrapped))
-                raw += p->match_value;
+                raw += p->match_value + 1;
         spin_unlock_irqrestore(&p->lock, flags);
 
         return value + raw;
@@ -478,7 +478,7 @@ static void sh_cmt_clock_event_start(struct sh_cmt_priv *p, int periodic)
         ced->min_delta_ns = clockevent_delta2ns(0x1f, ced);
 
         if (periodic)
-                sh_cmt_set_next(p, (p->rate + HZ/2) / HZ);
+                sh_cmt_set_next(p, ((p->rate + HZ/2) / HZ) - 1);
         else
                 sh_cmt_set_next(p, p->max_match_value);
 }
@@ -523,9 +523,9 @@ static int sh_cmt_clock_event_next(unsigned long delta,
 
         BUG_ON(ced->mode != CLOCK_EVT_MODE_ONESHOT);
         if (likely(p->flags & FLAG_IRQCONTEXT))
-                p->next_match_value = delta;
+                p->next_match_value = delta - 1;
         else
-                sh_cmt_set_next(p, delta);
+                sh_cmt_set_next(p, delta - 1);
 
         return 0;
 }