Resolution issue with kvm switch

[Alex Deucher]

On 7/5/07, Tom Winterhalder <t.winterhalder at freesurf.ch> wrote:
>
>
>  > Hi all,
> > I have several systems connected to a Level1 KVM switch. According
> > documentations this switch can handle resolutions up to 1920x1440.
> >
> > Now I have connected several Linux systems to this switch with different
> > graphic cards (ATI and Intel). Directly connected to my monitor (HP
> LP2465)
> > I get a resolution of 1920x1200 with all the systems. As soon as I connect
> > the systems to the switch and restart X I only get a resolution of
> > 1280x1024. Without restarting X, just connecting my systems to the switch
> I
> > still have the resolution of 1920x1200.
> >
> > Looking into the log files I can see, that the switch is reporting to
> > display resolutions of up to 1280x1024. So it is clearly a problem of the
> > switch not reporting correctly its capabilities. As I have no possibility
> to
> > upgrade the firmware of this switch I wonder if there is a way to override
> > these settings in xorg.conf.
> >
> > I already tried different Modelines and Mode settings without any success.
> > Can anyone help me solving this issue?
>
> Add a monitor section to your config with the appropriate sync ranges
>
>  The monitor section was already there. So I added the following lines
> (Values taken from monitor spec):
>
>          HorizSync   30-94
>          VertRefresh 48-85
>

Correct.

>
>  and modes for your monitor
>
>  How do I insert the correct modes here?  Using Modeline? Every Modeline I
> use lets X crash immediately after starting it.
>
>
>  then specify the modes you want in the
> display sub-section of the screen section of your config. That should
> do the trick.
>
>
>  My screen section looks like the following including the modes.
>  Section "Screen"
>          Identifier "aticonfig-Screen[0]"
>          Device     "aticonfig-Device[0]"
>          Monitor    "aticonfig-Monitor[0]"
>          DefaultDepth     24
>          SubSection "Display"
>                  Viewport   0 0
>                  Depth     24
>                  Modes   "1920x1200" "1600x1200" "1280x1024"
>          EndSubSection
>  EndSection
>

that looks fine.  please post your full log and config so we can see
what's going on.

Alex