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
---------
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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