Radeon Driver Default Display Resolution

Alex Deucher alexdeucher at gmail.com
Sun Mar 30 06:38:47 PDT 2008

On Tue, Mar 25, 2008 at 8:42 AM, Hamish <hamish at travellingkiwi.com> wrote:
> On Monday 24 March 2008 14:12:33 Alex Deucher wrote:
>  > On Mon, Mar 24, 2008 at 8:54 AM, Greg Treantos <gtreanto at gmail.com> wrote:
>  > > Thanks Alex adding the modelines worked. I tried Beso's suggestion first
>  > > without success. I have 2 follow up questions,
>  > >
>  > > 1) What changed in 7.3 that caused this issue?
>  >
>  > The radeon driver got xrandr 1.2 support.  Previous versions of the
>  > driver assumed one monitor per driver instance while with xrandr you
>  > may have several monitors.  With xrandr it is much more important to
>  > get mode information about each monitor since you may have two or more
>  > monitors connected with vastly different capabilities.  The previous
>  > version of the driver more or less always assumed a monitor was
>  > connected and forced whatever mode you specified.  You can still do
>  > this, but as you see, the configuration has changed a bit.  This page
>  > should give you a good overview:
>  > http://www.intellinuxgraphics.org/dualhead.html
>  >
>  Sorry to appropriate the thread, but I'm also running gentoo, and having a
>  VERY similar problem with my setup (Dual monitors, X300 graphics, xorg
>  ati/radeon drivers, 1024x768 VGA-0 LCD on left, 1680x1050 DVI-0 LCD on
>  right).
>  In my case the Xorg log file shows the modes being probed for the two
>  monitors... I've also been through the intelligraphics page and tried to
>  setup for static config... BUt mine still comes up with 1024x768 on both
>  monitors and requires xrandr to set 1680x1050 on the large monitor...

The "PreferredMode" option did not properly work with xserver 1.3  By
default xrandr tries to pick the closest mode possible supported by
each monitor rather than the preferred modes.

>  Admittedly the Screen section confuses me a bit... Why do I specify the total
>  virtual screensize of both monitors in the Screen section but the screen
>  section only references one of the monitor sections? Do I have that wrong?
>  (Although it seems the same as what www.intellinuxgraphics.org says).

The monitor in the screen section is irrelevant if you specify per
output monitors.  The screen defines the total desktop size in which
one or more monitors can be configured.


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