Re: suspend/restore almost works on Sony PCG-GRX570, acpi_video not good

From: John Baldwin <jhb_at_FreeBSD.org>
Date: Tue, 28 Jun 2005 13:41:20 -0400
On Monday 27 June 2005 06:57 pm, George Hartzell wrote:
> John Baldwin writes:
>  > On Sunday 19 June 2005 06:31 pm, George Hartzell wrote:
>  > > Hi,
>  > >
>  > > I'm working on a Sony PCG-GRX570.
>  > > [...]
>  >
>  > The problem is that your LCD isn't turned back on via DPMS, but there's
>  > not a good way to fix that always.  Especially if your BIOS doesn't
>  > support DPMS.
>
> Can you say a bit more about this?  When I suspend, the panel dims,
> but I can still read what's on the screen.  When I resume it never
> brightens, but I can still easily see what's there.  I never goes
> completely black.
>
> If I boot up into linux using a text console, it displays similar
> behaviour, dimming on suspend, but it brightens back up on resume.
>
> I *have* managed to get it to go completely black using a horribly
> hacked up version of acpi_video w/ the DPMS patches, but it still
> won't wake up.

The ACPI spec says that the OS is supposed to power down the attached monitor 
using DPMS before it shuts down the video controller and that it should turn 
the monitor back on using DPMS after it has resumed the video controller.  
FreeBSD currently just does the video controller parts (sort of) and doesn't 
do the DPMS stuff at all except in the patch to hack acpi_video, and that only 
works if your VGA BIOS supports DPMS and it can only work for the primary 
monitor even then.

-- 
John Baldwin <jhb_at_FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org
Received on Tue Jun 28 2005 - 16:14:52 UTC

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