Messages in this thread Patch in this message | | | From | Xunlei Pang <> | Subject | [PATCH 1/3] time: Don't bother to run rtc_resume() for nonstop clocksource | Date | Tue, 20 Jan 2015 16:41:28 +0000 |
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If a system does not provide a persistent_clock(), the time will be updated on resume by rtc_resume(). With the addition of the non-stop clocksources for suspend timing, those systems set the time on resume in timekeeping_resume(), but may not provide a valid persistent_clock().
This results in the rtc_resume() logic thinking no one has set the time and it then will over-write the suspend time again, which is not necessary and only increases clock error.
So, fix this for rtc_resume().
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> --- drivers/rtc/class.c | 2 +- include/linux/timekeeping.h | 11 +++++++++++ kernel/time/timekeeping.c | 3 ++- 3 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 472a5ad..c8f35a5 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -102,7 +102,7 @@ static int rtc_resume(struct device *dev) struct timespec64 sleep_time; int err; - if (has_persistent_clock()) + if (rtc_resume_skip()) return 0; rtc_hctosys_ret = -ENODEV; diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 9b63d13..6f3283b 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -238,6 +238,17 @@ extern void getnstime_raw_and_real(struct timespec *ts_raw, */ extern bool persistent_clock_exist; extern int persistent_clock_is_local; +extern bool suspendtime_found; + +#ifdef CONFIG_RTC_LIB +/* Used by rtc_resume() */ +static inline bool rtc_resume_skip(void) +{ + return suspendtime_found; +} +#else +static inline void rtc_resume_skip(void) { } +#endif static inline bool has_persistent_clock(void) { diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 6a93185..586bb5c 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -65,6 +65,7 @@ int __read_mostly timekeeping_suspended; /* Flag for if there is a persistent clock on this platform */ bool __read_mostly persistent_clock_exist = false; +bool suspendtime_found; static inline void tk_normalize_xtime(struct timekeeper *tk) { @@ -1178,8 +1179,8 @@ static void timekeeping_resume(void) struct timespec64 ts_new, ts_delta; struct timespec tmp; cycle_t cycle_now, cycle_delta; - bool suspendtime_found = false; + suspendtime_found = false; read_persistent_clock(&tmp); ts_new = timespec_to_timespec64(tmp); -- 1.9.1
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