[PATCH v2 2/2] clocksource: don't suspend/resume when unused
From: Thomas Gleixner <hidden>
Date: 2015-01-20 11:13:55
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On Fri, 16 Jan 2015, Alexandre Belloni wrote:
There is no point in calling suspend/resume for unused clocksources.
That's true, but ....
quoted hunk ↗ jump to hunk
Signed-off-by: Alexandre Belloni <redacted> --- kernel/time/clocksource.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 03cfc5a08e3b..da65b3b73a86 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c@@ -493,7 +493,7 @@ void clocksource_suspend(void) struct clocksource *cs; list_for_each_entry_reverse(cs, &clocksource_list, list) - if (cs->suspend) + if (cs->suspend && (cs->flags & CLOCK_SOURCE_USED)) cs->suspend(cs); }@@ -505,7 +505,7 @@ void clocksource_resume(void) struct clocksource *cs; list_for_each_entry(cs, &clocksource_list, list) - if (cs->resume) + if (cs->resume && (cs->flags & CLOCK_SOURCE_USED)) cs->resume(cs);
I had a deeper look at the clocksources which have a resume callback. We have implementations, which rely on the resume callback being called unconditionally. e.g.: arch/x86/kernel/hpet.c. And there are a few others which have extra PM code in the suspend/resume path independent of the fact whether the clocksource is enabled or not. So we really need to make this opt-in with a per clocksource flag. Thanks, tglx