Re: [PATCH] timekeeping: Add missing update call in timekeeping_resume()

[Konstantin Khlebnikov <khlebnikov@openvz.org>]

I run into the same regression in s2ram between v3.5-rc6 and v3.5-rc7.
This patch helps. Thanks.

Tested-by: Konstantin Khlebnikov <khlebnikov@openvz.org>

John Stultz wrote:
> From: Thomas Gleixner<tglx@linutronix.de>
>
> Linus,
> 	Since Thomas is on vacation I wanted to send you his fix to resolve
> the suspend regression from the leapsecond fixes.
>
> thanks
> -john
>
> The leap second rework unearthed another issue of inconsistent data.
>
> On timekeeping_resume() the timekeeper data is updated, but nothing
> calls timekeeping_update(), so now the update code in the timer
> interrupt sees stale values.
>
> This has been the case before those changes, but then the timer
> interrupt was using stale data as well so this went unnoticed for
> quite some time.
>
> Add the missing update call, so all the data is consistent everywhere.
>
> Reported-by: Andreas Schwab<schwab@linux-m68k.org>
> Reported-by-and-tested-by: "Rafael J. Wysocki"<rjw@sisk.pl>
> CC: LKML<linux-kernel@vger.kernel.org>
> Cc: Linux PM list<linux-pm@vger.kernel.org>
> Cc: John Stultz<johnstul@us.ibm.com>
> Cc: Ingo Molnar<mingo@kernel.org>
> Cc: Peter Zijlstra<a.p.zijlstra@chello.nl>,
> Cc: Prarit Bhargava<prarit@redhat.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Thomas Gleixner<tglx@linutronix.de>
> Signed-off-by: John Stultz<johnstul@us.ibm.com>
> ---
>   kernel/time/timekeeping.c |    1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> index 269b1fe..3447cfa 100644
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -717,6 +717,7 @@ static void timekeeping_resume(void)
>   	timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
>   	timekeeper.ntp_error = 0;
>   	timekeeping_suspended = 0;
> +	timekeeping_update(false);
>   	write_sequnlock_irqrestore(&timekeeper.lock, flags);
>
>   	touch_softlockup_watchdog();