Messages in this thread Patch in this message | | | From | Xunlei Pang <> | Subject | [PATCH v2 3/3] time: clocksource: Add a comment to CLOCK_SOURCE_SUSPEND_NONSTOP | Date | Thu, 22 Jan 2015 12:01:17 +0000 |
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When doing timekeeping_resume(), if the nonstop clocksource wraps back, "cycle_delta" will miss the wrap time.
It's hard to determine the right CLOCKSOURCE_MASK(xxx) or something to add code for inspecting such behavior, and we don't have many existent nonstop clocksources, so just add a comment to indicate that if have this flag set, people are aware that this nonstop clocksource won't wrap back during system suspend/resume.
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> --- include/linux/clocksource.h | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index abcafaa..8680189 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -207,6 +207,11 @@ struct clocksource { #define CLOCK_SOURCE_WATCHDOG 0x10 #define CLOCK_SOURCE_VALID_FOR_HRES 0x20 #define CLOCK_SOURCE_UNSTABLE 0x40 + +/* + * When setting this flag, you're also supposed to mean that it doesn't + * wrap back during system suspend/resume. See timekeeping_resume(). + */ #define CLOCK_SOURCE_SUSPEND_NONSTOP 0x80 #define CLOCK_SOURCE_RESELECT 0x100 -- 1.9.1
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