Messages in this thread | | | Date | Fri, 27 Feb 2015 10:00:00 +0000 | From | Lorenzo Pieralisi <> | Subject | Re: [PATCH 0/2] drivers: cpuidle: minor suspend-to-idle fixes |
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[CC'ed Preeti]
On Thu, Feb 26, 2015 at 11:37:54PM +0000, Rafael J. Wysocki wrote: > Me versions of the two $subject patches follow.
Thank you. I am testing them and I have run into the following issue.
Starting with:
3810631 ("PM / sleep: Re-implement suspend-to-idle handling")
the suspend-to-idle code path in the cpuidle_idle_call() bypasses the CPUIDLE_FLAG_TIMER_STOP code path entirely. Now, on most of the current ARM platforms, the deepest idle state loses the tick device context, therefore this means that going to idle through suspend-to-idle becomes a brute force way of nuking the tick, unless I am missing something here.
I am experiencing hangs on resume from suspend-to-idle when the broadcast timer is the broadast-hrtimer (ie there is no HW broadcast timer in the platform) and the deepest idle states lose the tick device context (ie they are CPUIDLE_FLAG_TIMER_STOP), I hope Preeti can help me test this on Power, still chasing the issue.
I could not reproduce the issue with a HW broadcast timer device.
Platform has deepest idle states that allow CPUs shutdown where the local tick device is gone on entry, I am trying to provide you with a backtrace, I need time to debug.
The question I have: is it safe to bypass the CPUIDLE_FLAG_TIMER_STOP and related broadcast mode entry/exit in the suspend-to-idle path ?
I do not think it is, but I am asking.
I can "force" tick freeze by initializing the enter_freeze pointer in the idle states (that's the next thing I will test), but still, for platforms where that's not possible my question above is still valid.
Thanks, Lorenzo
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