hw.acpi.reset_video behavior when multiple VGA cards are present

[Jung-uk Kim]

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On 2014-04-05 03:17:42 -0400, Johannes Meixner wrote:
> Hi,
> 
> I've originally posted the following to freebsd-acpi@ in February
> but didn't get any replies, so maybe someone here can help me out.
> 
> I've been trying to work out why my ASUS ZenBook can't work
> correctly with S3 sleepstates.
> 
> Resume works theoretically like a charm (I suspend with music
> playing; the music stops and continues upon wakeup; I can reboot
> the system blindly from command line).
> 
> One thing that does not, however, is VGA resume. The screen will
> just stay blank.
> 
> So I looked into it a little and realized -- what's the expected
> behaviour towards video reset when multiple VGA cards are present
> (NVIDIA Optimus) with vgapci0 being the (unusable) NVIDIA board and
> vgapci1 the (usable with Xorg, vt(9), KMS etc) Intel one?
> 
> As in, which card does `hw.acpi.reset_video` actually reset the
> video on?

It tries to call the reset vector of video BIOS.  In your
configuration, it probably won't do anything at all.

Jung-uk Kim
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