From 61973afc5912c4c22d21f0412c824cbac1d3ee3f Mon Sep 17 00:00:00 2001
From: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Date: Wed, 16 Jun 2010 08:10:21 +0900
Subject: [PATCH] sh: Fix overflow problem in get_ticks
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
---
arch/sh/lib/time.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/arch/sh/lib/time.c b/arch/sh/lib/time.c
index 9a8f89aef6..bc1656f73c 100644
--- a/arch/sh/lib/time.c
+++ b/arch/sh/lib/time.c
@@ -2,7 +2,7 @@
* (C) Copyright 2009
* Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
*
- * (C) Copyright 2007-2008
+ * (C) Copyright 2007-2010
* Nobobuhiro Iwamatsu <iwamatsu@nigauri.org>
*
* (C) Copyright 2003
@@ -36,6 +36,8 @@
#define TMU_MAX_COUNTER (~0UL)
static ulong timer_freq;
+static unsigned long last_tcnt;
+static unsigned long long overflow_ticks;
static inline unsigned long long tick_to_time(unsigned long long tick)
{
@@ -97,12 +99,26 @@ int timer_init (void)
tmu_timer_stop(0);
tmu_timer_start(0);
+ last_tcnt = 0;
+ overflow_ticks = 0;
+
return 0;
}
unsigned long long get_ticks (void)
{
- return 0 - readl(TCNT0);
+ unsigned long tcnt = 0 - readl(TCNT0);
+ unsigned long ticks;
+
+ if (last_tcnt > tcnt) { /* overflow */
+ overflow_ticks++;
+ ticks = (0xffffffff - last_tcnt) + tcnt;
+ } else {
+ ticks = tcnt;
+ }
+ last_tcnt = tcnt;
+
+ return (overflow_ticks << 32) | tcnt;
}
void __udelay (unsigned long usec)
--
2.39.5