> -----Original Message----- > From: Wood Scott-B07421 > Sent: Saturday, December 28, 2013 8:00 AM > To: Wang Dongsheng-B40534 > Cc: ga...@kernel.crashing.org; linuxppc-dev@lists.ozlabs.org > Subject: Re: [PATCH] powerpc/mpic_timer: fix the time calculation is not > accurate > > On Mon, 2013-12-23 at 10:33 +0800, Dongsheng Wang wrote: > > From: Wang Dongsheng <dongsheng.w...@freescale.com> > > > > When the timer GTCCR toggle bit is inverted, we calculated the rest of > > the time is not accurate. So we need to ignore this bit. > > > > Signed-off-by: Wang Dongsheng <dongsheng.w...@freescale.com> > > > > diff --git a/arch/powerpc/sysdev/mpic_timer.c > > b/arch/powerpc/sysdev/mpic_timer.c > > index 22d7d57..0fb70c9 100644 > > --- a/arch/powerpc/sysdev/mpic_timer.c > > +++ b/arch/powerpc/sysdev/mpic_timer.c > > @@ -41,6 +41,7 @@ > > #define MPIC_TIMER_TCR_ROVR_OFFSET 24 > > > > #define TIMER_STOP 0x80000000 > > +#define GTCCR_TOG 0x80000000 > > #define TIMERS_PER_GROUP 4 > > #define MAX_TICKS (~0U >> 1) > > #define MAX_TICKS_CASCADE (~0U) > > @@ -96,8 +97,15 @@ 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; > > + > > + /* > > + * In some cases tmp_sec may be greater than ticks, because in the > > + * process of calculation ticks and tmp_sec will be rounded. > > + */ > > + if (tmp_sec <= ticks) > > + time->tv_usec = (__kernel_suseconds_t) > > + div_u64((ticks - tmp_sec) * 1000000, priv->timerfreq); > > I don't see how this part of the patch relates to the patch description. > Thanks, I miss this description, :(. I should split the patch.
-Dongsheng > -Scott > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
