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); return; } @@ -327,11 +335,13 @@ void mpic_get_remain_time(struct mpic_timer *handle, struct timeval *time) casc_priv = priv->timer[handle->num].cascade_handle; if (casc_priv) { tmp_ticks = in_be32(&priv->regs[handle->num].gtccr); + tmp_ticks &= ~GTCCR_TOG; ticks = ((u64)tmp_ticks & UINT_MAX) * (u64)MAX_TICKS_CASCADE; tmp_ticks = in_be32(&priv->regs[handle->num - 1].gtccr); ticks += tmp_ticks; } else { ticks = in_be32(&priv->regs[handle->num].gtccr); + ticks &= ~GTCCR_TOG; } convert_ticks_to_time(priv, ticks, time); -- 1.8.5 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev