Messages in this thread | | | Date | Thu, 25 Apr 2013 09:13:32 -0700 | From | John Stultz <> | Subject | Re: CONFIG_RTC_HCTOSYS lost on x86 with ALWAYS_USE_PERSISTENT_CLOCK changes? |
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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.
thanks -john
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