kern/73823: [request] acpi / power-on by timer support

[Andriy Gapon]

The following reply was made to PR kern/73823; it has been noted by GNATS.

From: Andriy Gapon <avg at icyb.net.ua>
To: AW <arne_woerner at yahoo.com>
Cc: bug-followup at FreeBSD.org, Bruce Cran <brucec at FreeBSD.org>
Subject: Re: kern/73823: [request] acpi / power-on by timer support
Date: Mon, 06 Sep 2010 10:14:45 +0300

 on 06/09/2010 09:54 AW said the following:
 >> Can someone (Bruce?) explain to me in greater detail what this PR is about?
 >>
 > I believed that the box can boot at the specified time if Linux powers it down...
 > and that it cant, if FreeBSD does it...
 > 
 >> I thought that the functionality of turning power on at certain time completely
 >> belonged to BIOS.  How is acpi(4) driver expected to help?
 >>
 > i dont know... maybe the power down procedure offers some flag
 > (like "power down, but honor the BIOS settings about wake-up time" and
 > "power down and ignore BIOS settings about wake-up time")?
 > That LAN wake-up packet worked fine (WOL?) if FreeBSD powered the box down...
 > 
 > Maybe i used a different/buggy BIOS when I found the problem?
 > Maybe Linux couldnt do it, too...?
 > 
 > I dont use that box (mainboard: ECS K7VVM+ or so)/FreeBSD anymore,
 > but it should be easy for u to test it on contemporary hardware...
 
 Well, I am not aware of any OS assistance or control over this.
 If hardware and BIOS support this feature and it is properly configured, then
 power-on happens entirely in hardware and for OS it looks just like a normal boot.
 
 BTW, an interesting page:
 http://www.mythtv.org/wiki/ACPI_Wakeup
 It mentions that BIOS would disable wake up if hardware clock is modified later.
 We do that.
 
 -- 
 Andriy Gapon