Hi,
On 18/07/2017 at 10:25:23 -0700, Mark Salyzyn wrote:
> Go directly to the rtc for persistent wall clock time and print.
> Useful if REALTIME is required to be logged in a low level power
> management function or when clock activities are suspended. An
> aid to permit user space alignment of kernel activities.
>
> Feature activated by CONFIG_RTC_SHOW_TIME.
>
> Signed-off-by: Mark Salyzyn <salyzyn@xxxxxxxxxxx>
> ---
> drivers/rtc/Kconfig | 11 +++++++++++
> drivers/rtc/rtc-lib.c | 16 ++++++++++++++++
> include/linux/rtc.h | 5 +++++
> 3 files changed, 32 insertions(+)
>
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 72419ac2c52a..7c308605bf42 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -5,6 +5,17 @@
> config RTC_LIB
> bool
>
> +config RTC_SHOW_TIME
> + bool "rtc_show_time instrumentation"
> + select RTC_LIB
> + help
> + Activate rtc_show_time(const char *msg) wall clock time
> + instrumentation.
> +
> + The instrumentation is used to help triage and synchronize
> + kernel logs using CLOCK_MONOTONIC and user space activity
> + logs utilizing CLOCK_REALTIME references.
> +
> config RTC_MC146818_LIB
> bool
> select RTC_LIB
> diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c
> index 1ae7da5cfc60..676d6a83e843 100644
> --- a/drivers/rtc/rtc-lib.c
> +++ b/drivers/rtc/rtc-lib.c
> @@ -94,6 +94,22 @@ void rtc_time64_to_tm(time64_t time, struct rtc_time *tm)
> }
> EXPORT_SYMBOL(rtc_time64_to_tm);
>
> +#ifdef CONFIG_RTC_SHOW_TIME
> +void rtc_show_time(const char *prefix_msg)
> +{
> + struct timespec ts;
> + struct rtc_time tm;
> +
> + getnstimeofday(&ts);
> + rtc_time_to_tm(ts.tv_sec, &tm);
Apart from using rtc_time_to_tm (and you should probably use
rtc_time64_to_tm), none of this is actually related to the RTC
subsystem. I feel like you should find another place to put that, maybe
timekeeping_debug.c?
> + pr_info("%s %d-%02d-%02d %02d:%02d:%02d.%09lu UTC\n",
> + prefix_msg ? prefix_msg : "Time:",
> + tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
> + tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
> +}
> +EXPORT_SYMBOL(rtc_show_time);
> +#endif
> +
> /*
> * Does the rtc_time represent a valid date/time?
> */
> diff --git a/include/linux/rtc.h b/include/linux/rtc.h
> index 0a0f0d14a5fb..bf625e023799 100644
> --- a/include/linux/rtc.h
> +++ b/include/linux/rtc.h
> @@ -22,6 +22,11 @@ extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year
> extern int rtc_valid_tm(struct rtc_time *tm);
> extern time64_t rtc_tm_to_time64(struct rtc_time *tm);
> extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm);
> +#ifdef CONFIG_RTC_SHOW_TIME
> +extern void rtc_show_time(const char *prefix_msg);
> +#else
> +#define rtc_show_time(prefix_msg)
> +#endif
> ktime_t rtc_tm_to_ktime(struct rtc_time tm);
> struct rtc_time rtc_ktime_to_tm(ktime_t kt);
>
> --
> 2.13.2.932.g7449e964c-goog
>
--
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
