[ltp] Radeon: hot-swap VGA-out monitor

[Christopher Singley]

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Thanks for the responses.

Mario, your trick works for me. =A0In xorg.conf, I set the following option=
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(irrelevant directives deleted):
Section "Device"
        Identifier      "ATI Radeon"
        Driver          "radeon"
        Option          "MergedFB"              "on"
        Option  "MetaModes"     "1024x768-1024x768 1024x768"
        Option          "MonitorLayout"         "LVDS,TMDS"
EndSection

This forces X to think both monitors are attached, and always enables xrand=
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to switch between single/dual-head modes.

However, it's also a bit of a brute-force hack... the notebook always comes=
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in dual-head mode, even when nothing is plugged in, so the cursor will scro=
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off the edge of the screen.

As a convenience, I bound`xrandr -s 1` and `xrandr -s 0` scripts to be=20
executed by those odd little forward/back buttons the Thinkpad keyboard=20
places next to the cursor arrows.  However, I really would prefer to set up=
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fully automatic solution.

Is there somewhere I can nose around inside of /sys or /proc to detect what=
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monitors are attached?

Andrey, do you have any idea how the monitor hotplug works in Xorg 7.3?  I=
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read the release notes, which say that this functionality is implemented by=
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xrandr 1.2; however, I already have xrandr 1.2.0 installed on my machine, s=
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I'm not sure it will give me anything I don't already have.

Thanks again for the help.

cs

On Thursday 06 September 2007 14:05:02 Mario Theodoridis wrote:
> i've had this setup on a t42p.
> I found the trick to be to specify monitor settings and not let them be
> auto detected. Xorg.conf attached.
>
> This was using it with my old Viewsonic GS815 on xorg 6.8. It also worked
> well with projectors.
>
>
> mario;>
>
> So, Andrey Kislyuk wrote:
> > Monitor hotplug is in Xorg 7.3, which was released today. All you have
> > to do is wait for it to hit your distribution.
> >
> > Christopher Singley wrote:
> >> I have a Thinkpad R51 with an ATI Radeon 250 graphics card.  The card
> >> has a  VGA out port, and I like to run in dual-head configuration
> >> (external monitor  attached) using the MergedFB options of the Radeon
> >> X driver.
> >>
> >> This generally works well; however I'd like to be able to hot-swap
> >> monitors &  toggle at will between single-head & dual-head
> >> configuration.
> >>
> >> Using the radeon driver's "MergedFBAuto" option works to allow X to
> >> autodetect  single/dual-head configuration when it starts up.  If it
> >> starts up in  dual-head mode, setting "MetaModes" like
> >> "1024x768-1024x768 1024x768"  additionally allows me to use xrandr to
> >> dynamically switch back & forth  between single/dual-head when I
> >> plug/unplug the external monitor.
> >>
> >> However, if no external monitor is detected when X starts up, I don't
> >> know how  to force a configuration so that when I subsequently plug in
> >> an external  monitor, I can switch over to dual-head configuration on
> >> the fly without  restarting X.
> >>
> >> I imagine this must be a feature desired by many people other than
> >> just me.   Can anyone give me a hint how to set this up?
> >>
> >> Thanks,
> >> cs
> >
> > --
> > The linux-thinkpad mailing list home page is at:
> > http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad



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Christopher Singley, CFA
President, Singley Capital Management, Inc.
tel (713) 459-0881