Re: [PATCH v4 0/4] Add support for S3 non-stop TSC support.

From: John Stultz
Date: Wed Mar 13 2013 - 15:17:35 EST

On 03/11/2013 08:56 PM, Feng Tang wrote:
Hi All,

On some new Intel Atom processors (Penwell and Cloverview), there is
a feature that the TSC won't stop in 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.h and timekeeping.c to support and utilizing

The major change to timekeeping is the way to count suspended time,
current way is trying to use the persistent clock first, and then
try the rtc if persistent clock can't do it. This patch will change
the trying order to:
suspend-nonstop clocksource -> persistent clock -> rtc

Please help to review them, thanks a lot!


I've gone ahead and queued these, with my minor modifications, for 3.10 (pending further testing).


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