Cannot change resolution on old iBook G3 equipped with ATI Rage M3

[Alex Deucher]

On Nov 30, 2007 6:13 AM, Riccardo Murri <riccardo.murri at gmail.com> wrote:
> Hello,
>
> I recently purchased an old iBook equipped with a Rage M3 (from
> `lspci` output)::
>
>    0000:00:10.0 VGA compatible controller: \
>      ATI Technologies Inc Rage Mobility M3 AGP 2x (rev 02)
>
> I installed Ubuntu Feisty (xserver-xorg 1.2.0-3ubunut8,
> xserver-xorg-video-ati 6.6.3-2ubuntu6) and configured `xorg.conf` so
> to enable the standard resolutions 1024x768, 800x600 and 640x480.
> This is the output from `xrandr -q`::
>
>    SZ:    Pixels          Physical       Refresh
>   *0   1024 x 768    ( 347mm x 260mm )  *60
>    1    800 x 600    ( 347mm x 260mm )   60
>    2    640 x 480    ( 347mm x 260mm )   60
>    3    640 x 384    ( 347mm x 260mm )   60
>    4    512 x 384    ( 347mm x 260mm )   60
>    5    400 x 300    ( 347mm x 260mm )   60
>    6    320 x 240    ( 347mm x 260mm )   60
>   Current rotation - normal
>   Current reflection - none
>   Rotations possible - normal
>   Reflections possible - none
>
> However, when I try to change the resolution with to 800x600 (`xrandr
> -s1`) I get a corrupted display:
>   - the lower-res desktop is visible in the upper left portion of the
>     display;
>   - a black band is displayed on the right portion of the LCD panel;
>   - the upper portion of the visible screen is replicated down left on
>     the LCD panel;
>   - between the upper portion and the lower portion of the panel, a
>     band of random junk is displayed, as wide as the LCD panel.
>
> At 640x400, things are even worse.
>
> I have tried every suggestion I could Googling (setting depth to
> 16bpp, fiddling with options in xorg.conf, etc.), to no extent.
> The Apple specs for the iBook say that the LCD is 1024x768 but that
> the video card would scale lower-res images to the panel size.
> Indeed, it works on some other (more recent) iBook that I have.

It might be a problem with the r128 fbdev driver.  try setting:
Option          "UseFBDev"              "false"
That will use the use the native driver code to change modes and will
also allow you to use zaphod style dualhead if you want.

Alex