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| author | Baolin Wang <baolin.wang@linaro.org> | 2018-07-17 10:55:16 +0300 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2018-07-20 03:08:52 +0300 |
| commit | 39232ed5a1793f67b11430c43ed8a9ed6e96c6eb (patch) | |
| tree | dbcd15f6322432bf49f1c0d84fe638ccf7189117 /include/linux/clocksource.h | |
| parent | f473e5f467f6049370575390b08dc42131315d60 (diff) | |
| download | linux-39232ed5a1793f67b11430c43ed8a9ed6e96c6eb.tar.xz | |
time: Introduce one suspend clocksource to compensate the suspend time
On some hardware with multiple clocksources, we have coarse grained
clocksources that support the CLOCK_SOURCE_SUSPEND_NONSTOP flag, but
which are less than ideal for timekeeping whereas other clocksources
can be better candidates but halt on suspend.
Currently, the timekeeping core only supports timing suspend using
CLOCK_SOURCE_SUSPEND_NONSTOP clocksources if that clocksource is the
current clocksource for timekeeping.
As a result, some architectures try to implement read_persistent_clock64()
using those non-stop clocksources, but isn't really ideal, which will
introduce more duplicate code. To fix this, provide logic to allow a
registered SUSPEND_NONSTOP clocksource, which isn't the current
clocksource, to be used to calculate the suspend time.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
[jstultz: minor tweaks to merge with previous resume changes]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'include/linux/clocksource.h')
| -rw-r--r-- | include/linux/clocksource.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 7dff1963c185..308918928767 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -194,6 +194,9 @@ extern void clocksource_suspend(void); extern void clocksource_resume(void); extern struct clocksource * __init clocksource_default_clock(void); extern void clocksource_mark_unstable(struct clocksource *cs); +extern void +clocksource_start_suspend_timing(struct clocksource *cs, u64 start_cycles); +extern u64 clocksource_stop_suspend_timing(struct clocksource *cs, u64 now); extern u64 clocks_calc_max_nsecs(u32 mult, u32 shift, u32 maxadj, u64 mask, u64 *max_cycles); |