Messages in this thread | | | From | Feng Tang <> | Subject | [RFC PATCH 0/5] Add support for S3 non-stop TSC support. | Date | Mon, 21 Jan 2013 14:38:40 +0800 |
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Hi All,
On some new Intel Atom processors (Penwell and Cloverview), there is a feature that the TSC won't stop S3, say the TSC value won't be reset to 0 after resume. This feature makes TSC a more reliable clocksource and could benefit the timekeeping code during system suspend/resume cycles.
The enabling efforts include adding new flags for this feature, modifying clocksource.c and timekeeping.c to support and utilizing it.
One remaining question is inside the timekeeping_resume(), we don't know if it is called by resuming from suspend(s2ram) or from hibernate(s2disk), as there is no easy way to check it currently. But it doesn't hurt as these Penwell/Cloverview platforms only have S3 state, and no S4.
Please help to review them, thanks!
- Feng
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Feng Tang (5): x86: Add cpu capability flag X86_FEATURE_TSC_S3_NOTSTOP clocksource: Add new feature flag CLOCK_SOURCE_SUSPEND_NOTSTOP x86: tsc: Add support for new S3_NOTSTOP feature clocksource: Enlarge the maxim time interval when configuring the scale and shift timekeeping: Add support for clocksource which doesn't stop during suspend
arch/x86/include/asm/cpufeature.h | 1 + arch/x86/kernel/cpu/intel.c | 12 ++++++++++++ arch/x86/kernel/tsc.c | 6 +++++- include/linux/clocksource.h | 1 + kernel/time/clocksource.c | 6 +++--- kernel/time/timekeeping.c | 23 ++++++++++++++++++----- 6 files changed, 40 insertions(+), 9 deletions(-)
-- 1.7.9.5
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