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| author |   Wang Dongsheng <dongsheng.wang@freescale.com> | 2014-01-06 13:23:31 +0800 |
|---|---|---|
| committer |   Scott Wood <scottwood@freescale.com> | 2014-01-09 17:52:14 -0600 |
| commit | d2dc13b5339c657e526c405888df69d99322a016 (patch) | |
| tree | 8c9c822cdeda7cc193a76c8fc5b4bc82d00d8d75 | |
| parent | powerpc/mpic_timer: fix the time is not accurate caused by GTCRR toggle bit (diff) | |
| download | linux-dev-d2dc13b5339c657e526c405888df69d99322a016.tar.xz linux-dev-d2dc13b5339c657e526c405888df69d99322a016.zip | |
powerpc/mpic_timer: fix convert ticks to time subtraction overflow
In some cases tmp_sec may be greater than ticks, because in the process
of calculation ticks and tmp_sec will be rounded.
Signed-off-by: Wang Dongsheng <dongsheng.wang@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
| -rw-r--r-- | arch/powerpc/sysdev/mpic_timer.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/powerpc/sysdev/mpic_timer.c b/arch/powerpc/sysdev/mpic_timer.c index 70dcf9c5b8fb..9d9b06217f8b 100644 --- a/arch/powerpc/sysdev/mpic_timer.c +++ b/arch/powerpc/sysdev/mpic_timer.c @@ -97,8 +97,11 @@ static void convert_ticks_to_time(struct timer_group_priv *priv, time->tv_sec = (__kernel_time_t)div_u64(ticks, priv->timerfreq); tmp_sec = (u64)time->tv_sec * (u64)priv->timerfreq; - time->tv_usec = (__kernel_suseconds_t) - div_u64((ticks - tmp_sec) * 1000000, priv->timerfreq); + time->tv_usec = 0; + + if (tmp_sec <= ticks) + time->tv_usec = (__kernel_suseconds_t) + div_u64((ticks - tmp_sec) * 1000000, priv->timerfreq); return; } |