Re: [RFC PATCH v2 5/9] rtc/mc13xxx: Update driver to address y2038/y2106 issues

[Xunlei Pang]

Cc Uwe Kleine-Koenig <u.kleine-koenig@xxxxxxxxxxxxxx>

On 13 January 2015 at 23:44, Xunlei Pang <xlpang@xxxxxxx> wrote:
> From: Xunlei Pang <pang.xunlei@xxxxxxxxxx>
>
> This driver has a number of y2038/y2106 issues.
>
> This patch resolves them by:
> - Replace rtc_time_to_tm() with rtc_time64_to_tm()
> - Change mc13xxx_rtc_set_mmss() to use rtc_class_ops's set_mmss64()
>
> After this patch, the driver should not have any remaining
> y2038/y2106 issues.
>
> Signed-off-by: Xunlei Pang <pang.xunlei@xxxxxxxxxx>
> ---
>  drivers/rtc/rtc-mc13xxx.c | 32 ++++++++++++++------------------
>  1 file changed, 14 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c
> index 5bce904b..32df1d8 100644
> --- a/drivers/rtc/rtc-mc13xxx.c
> +++ b/drivers/rtc/rtc-mc13xxx.c
> @@ -83,20 +83,19 @@ static int mc13xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
>                         return ret;
>         } while (days1 != days2);
>
> -       rtc_time_to_tm(days1 * SEC_PER_DAY + seconds, tm);
> +       rtc_time64_to_tm((time64_t)days1 * SEC_PER_DAY + seconds, tm);
>
>         return rtc_valid_tm(tm);
>  }
>
> -static int mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs)
> +static int mc13xxx_rtc_set_mmss(struct device *dev, time64_t secs)
>  {
>         struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
>         unsigned int seconds, days;
>         unsigned int alarmseconds;
>         int ret;
>
> -       seconds = secs % SEC_PER_DAY;
> -       days = secs / SEC_PER_DAY;
> +       days = div_s64_rem(secs, SEC_PER_DAY, &seconds);
>
>         mc13xxx_lock(priv->mc13xxx);
>
> @@ -159,7 +158,7 @@ static int mc13xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
>  {
>         struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
>         unsigned seconds, days;
> -       unsigned long s1970;
> +       time64_t s1970;
>         int enabled, pending;
>         int ret;
>
> @@ -189,10 +188,10 @@ out:
>         alarm->enabled = enabled;
>         alarm->pending = pending;
>
> -       s1970 = days * SEC_PER_DAY + seconds;
> +       s1970 = (time64_t)days * SEC_PER_DAY + seconds;
>
> -       rtc_time_to_tm(s1970, &alarm->time);
> -       dev_dbg(dev, "%s: %lu\n", __func__, s1970);
> +       rtc_time64_to_tm(s1970, &alarm->time);
> +       dev_dbg(dev, "%s: %lld\n", __func__, (long long)s1970);
>
>         return 0;
>  }
> @@ -200,8 +199,8 @@ out:
>  static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
>  {
>         struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
> -       unsigned long s1970;
> -       unsigned seconds, days;
> +       time64_t s1970;
> +       u32 seconds, days;
>         int ret;
>
>         mc13xxx_lock(priv->mc13xxx);
> @@ -215,20 +214,17 @@ static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
>         if (unlikely(ret))
>                 goto out;
>
> -       ret = rtc_tm_to_time(&alarm->time, &s1970);
> -       if (unlikely(ret))
> -               goto out;
> +       s1970 = rtc_tm_to_time64(&alarm->time);
>
> -       dev_dbg(dev, "%s: o%2.s %lu\n", __func__, alarm->enabled ? "n" : "ff",
> -                       s1970);
> +       dev_dbg(dev, "%s: o%2.s %lld\n", __func__, alarm->enabled ? "n" : "ff",
> +                       (long long)s1970);
>
>         ret = mc13xxx_rtc_irq_enable_unlocked(dev, alarm->enabled,
>                         MC13XXX_IRQ_TODA);
>         if (unlikely(ret))
>                 goto out;
>
> -       seconds = s1970 % SEC_PER_DAY;
> -       days = s1970 / SEC_PER_DAY;
> +       days = div_s64_rem(s1970, SEC_PER_DAY, &seconds);
>
>         ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days);
>         if (unlikely(ret))
> @@ -268,7 +264,7 @@ static irqreturn_t mc13xxx_rtc_update_handler(int irq, void *dev)
>
>  static const struct rtc_class_ops mc13xxx_rtc_ops = {
>         .read_time = mc13xxx_rtc_read_time,
> -       .set_mmss = mc13xxx_rtc_set_mmss,
> +       .set_mmss64 = mc13xxx_rtc_set_mmss,
>         .read_alarm = mc13xxx_rtc_read_alarm,
>         .set_alarm = mc13xxx_rtc_set_alarm,
>         .alarm_irq_enable = mc13xxx_rtc_alarm_irq_enable,
> --
> 1.9.1
>
>
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