Waking system up from suspend-to-ram at specified time.

Piotr Czachur zimnyx at gmail.com
Mon Jul 30 23:09:06 UTC 2012


Thank you for wind of hope :)

2012/7/30 Ian Smith <smithi at nimnet.asn.au>:
> On my Thinkpad T23, BIOS autostart (not autoresume) time setting also
> works only from a cold start.  WoL also worked from 'off' but not from
> S3, but that was on 8.1-STABLE.  What version are you running, and on
> what machine?  Some reports indicate success may depend on which BIOS.

I'm running FreeBSD 9.0 on Pentium 4 (Dell SX270).
WoL wakes my box up from "off" and S3, and BIOS "Auto power on" just from "off".

> I'll forward you offlist a couple of never-completed drafts that turned
> up in postponed messages from 2010 while hunting mail about this, to
> (bcc'd) avg@, brucec@ and mav@, after researching this in response to an
> ACPI PR: http://www.freebsd.org/cgi/query-pr.cgi?pr=kern%2F73823&cat=

Thanks. Nice to know this.

> Then at least, you also had to modify Linux shutdown behaviour to avoid
> writing the clocktime back to the RTC if a wake time had been set, as
> RTC writes did not preserve the RTC wake interrupt bit, for some reason.

Is this RTC writing supposed to disable "Auto power on" alarm set via BIOS?
In my situation it's not the case, my box is shut down from cron
(shutdown -h) , and powers on automaticaly next morning.

> FreeBSD also does not preserve (gratuitously zeroes) that bit on all RTC
> writes, which is easily enough fixable, mostly in writertc.c, with few
> other places needing mods that I could see.  Ah yes, plus a (cleanroom)
> utility not unlike rtcwake, but once writertc() is fixed that should be
> relatively trivial, without needing to mess with the shutdown code.

So the reason of not waking up from S3, is RTC Wake bit zeroed during go to S3?

> Present circumstances don't permit me to work on this further, but I do
> think it could be a worthwhile and not so hard project for 'someone' :)

Deal :)
I'd start from enabling wake up from S3 using BIOS "Auto power on", and
leave setting RTC alarm from running system as next step.


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