From: John Stultz
Date: Thu Apr 25 2013 - 12:13:39 EST

On 04/25/2013 12:11 AM, Alexander Holler wrote:
Am 24.04.2013 18:07, schrieb John Stultz:

And why is RTC_SYSTOHC now gone on x86?

So summarizing the above, because as much as I'm aware, its always been
redundant and unnecessary on x86. Thus being able at build time to mark
it as unnecessary was attractive, since it reduced the code paths
running at suspend/resume.

Hmm, I thought RTC_SYSTOHC was there to update the used RTC clock with the time from NTP (and liked that). Therefor I don't understand why it is redundant and unnecessary on x86. Of course, most systems do have something in userspace to set the RTC on shutdown, so it isn't really needed.

Prior to SYSTOHC being introduced, we only synced system time to the RTC via update_persistent_clock() on systems that had that interface. SYSTOHC is relatively new and lets the system sync to RTCs that don't have the persistent clock.


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