On 20 April 2018 at 23:22, Arnd Bergmann <a...@arndb.de> wrote:
> On Thu, Apr 19, 2018 at 8:22 AM, Baolin Wang <baolin.w...@linaro.org> wrote:
>> The read_persistent_clock() uses a timespec, which is not year 2038 safe
>> on 32bit systems. Moreover on m68k architecture, we have implemented generic
>> RTC drivers that can be used to compensate the system suspend time. So
>> we can remove the obsolete read_persistent_clock().
>>
>> Signed-off-by: Baolin Wang <baolin.w...@linaro.org>
>
> I'm not sure about this one: it's still possible to turn off
> CONFIG_RTC_DRV_GENERIC
> on M68KCLASSIC, and in that case we still need a read_persistent_clock64()
> implementation. Or we use your patch but make CONFIG_RTC_DRV_GENERIC
> mandatory.
OK. Thanks for fixing the issue with your patch.
>
> See below for a version I did a while ago (but never submitted as I got
> distracted).
>
> Arnd
>
> commit 13ddf5a33a195e9b7a7a6ed10481363b5259c1d4
> Author: Arnd Bergmann <a...@arndb.de>
> Date: Thu Jan 25 15:30:50 2018 +0100
>
> m68k: use read_persistent_clock64 consistently
>
> We have two ways of getting the current time from a platform at boot
> or during suspend: either using read_persistent_clock() or the rtc
> class operation. We never need both, so I'm hiding the
> read_persistent_clock variant when the generic RTC is enabled.
>
> Since read_persistent_clock() and mktime() are deprecated because of
> the y2038 overflow of time_t, we should use the time64_t based
> replacements here.
>
> Finally, the dependency on CONFIG_ARCH_USES_GETTIMEOFFSET looks
> completely bogus in this case, so let's remove that. It was
> added in commit b13b3f51ff7b ("m68k: fix inclusion of
> arch_gettimeoffset for non-MMU 68k classic CPU types") to deal
> with arch_gettimeoffset(), which has since been removed from
> this file and is unrelated to the RTC functions.
>
> The rtc accessors are only used by classic machines, while
> coldfire uses proper RTC drivers, so we can put the old
> ifdef back around both functions.
>
> Signed-off-by: Arnd Bergmann <a...@arndb.de>
>
> diff --git a/arch/m68k/kernel/time.c b/arch/m68k/kernel/time.c
> index 97dd4e26f234..edcf3855d8b0 100644
> --- a/arch/m68k/kernel/time.c
> +++ b/arch/m68k/kernel/time.c
> @@ -71,7 +71,9 @@ static irqreturn_t timer_interrupt(int irq, void *dummy)
> return IRQ_HANDLED;
> }
>
> -void read_persistent_clock(struct timespec *ts)
> +#ifdef CONFIG_M68KCLASSIC
> +#if !IS_BUILTIN(CONFIG_RTC_DRV_GENERIC)
> +void read_persistent_clock64(struct timespec64 *ts)
> {
> struct rtc_time time;
> ts->tv_sec = 0;
> @@ -82,12 +84,13 @@ void read_persistent_clock(struct timespec *ts)
>
> if ((time.tm_year += 1900) < 1970)
> time.tm_year += 100;
> - ts->tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
> + ts->tv_sec = mktime64(time.tm_year, time.tm_mon, time.tm_mday,
> time.tm_hour, time.tm_min, time.tm_sec);
> }
> }
> +#endif
>
> -#if defined(CONFIG_ARCH_USES_GETTIMEOFFSET) &&
> IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
> +#if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
> static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
> {
> mach_hwclk(0, tm);
> @@ -145,8 +148,8 @@ static int __init rtc_init(void)
> }
>
> module_init(rtc_init);
> -
> -#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */
> +#endif /* CONFIG_RTC_DRV_GENERIC */
> +#endif /* CONFIG M68KCLASSIC */
>
> void __init time_init(void)
> {
--
Baolin.wang
Best Regards
