[PATCH] clocksource: sh_cmt: One-off clockevent fix

[PATCH] clocksource: sh_cmt: One-off clockevent fix

[Magnus Damm]

From: Magnus Damm <damm@opensource.se>

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

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

Reported-by: Hideki EIRAKU <hdk@igel.co.jp>
Signed-off-by: Magnus Damm <damm@opensource.se>
---

 drivers/clocksource/sh_cmt.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- 0006/drivers/clocksource/sh_cmt.c
+++ work/drivers/clocksource/sh_cmt.c	2010-08-02 17:43:08.000000000 +0900
@@ -478,7 +478,7 @@ static void sh_cmt_clock_event_start(str
 	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(unsig
 
 	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;
 }

[PATCH] clocksource: sh_cmt: One-off clockevent fix V2

[Magnus Damm]

From: Magnus Damm <damm@opensource.se>

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>
---

 Changes since V1:
 - the clocksource counter need to be adjusted as well

 drivers/clocksource/sh_cmt.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- 0006/drivers/clocksource/sh_cmt.c
+++ work/drivers/clocksource/sh_cmt.c	2010-08-04 13:21:21.000000000 +0900
@@ -308,7 +308,7 @@ static irqreturn_t sh_cmt_interrupt(int 
 	 * 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(s
 	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(str
 	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(unsig
 
 	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;
 }