[ltp] F7 Video Switching on a T42?

[Identity Guarded]

On Tuesday 14 March 2006 2:58 pm, Marius Gedminas mgedmin-at-b4net.lt |
Linux-Thinkpad| wrote:
> On Thinkpads you can perform video switching by doing
>
>   echo video_switch > /proc/acpi/ibm/video
>
> It is possible to bind that command to the ACPI event generated by
> Fn-F7.

I remember playing around this.  It didn't work.  If I didn't have acpid=20
manage F7 events, then as I remember ibm_acpi would blank my LCD and I=20
couldn't figure out a way to get my display back without rebooting the=20
machine.

> (Nowadays I use MergedFB for true dual-head mode, and I can switch between
> single-head and dual-head with xrandr.  I never had to fiddle with
> /proc/acpi/ibm/video or Fn-F7 to get output on the external screen, but
> then again I never wanted "LCD only" or "CRT only" output modes.)

I'm with Shem on this one.  It would be nice to not waste the power driving
an output that's not in use.  The only way I could figure out to cut power=
=20
from the CRT output is to restart X with the monitor plugged.

> The radeon driver also has an option
>
>        Option "BIOSHotkeys" "boolean"
>               Enable  BIOS  hotkey  output  switching. This allows the BI=
OS
> to toggle outputs using hotkeys (e.g.,  fn-f7,  etc.).   Since  the drive=
r=20
> does not support ACPI, there is no way to validate modes on an output
> switch and the BIOS can potentially  change  things behind the driver=E2=
=80=99s
> back.  The default is off.

I kind of remember reading about this one, but I don't recall messing aroun=
d=20
with it.  I'll give it a whirl when I have more time. =20

Thanks for the prompt responses everyone.

=2D Sukant