Radeon KMS extremely slow on RS600

[Alex Deucher]

2009/12/2 Dariem Pérez Herrera <dariemp at uci.cu>:
> Hello,
> I'm using a GPU RS600. This has always been a problematic GPU for free
> radeon drivers since I have my notebook (more than a year). I've never
> riched more than 320 fps, and as average I'm always running at 190 fps
> more or less. Right now, I'm testing latest kernel RC with radeon KMS
> feature activated, latest xf86-video-ati from git, latest libdrm, latest
> mesa. I'm having a very slow speed experience with my graphics:  55 fps.
> I'm also noting some totally white screens in certain times, during
> initializations of graphic modes, but later it recovers (but again, with
> very slow speed). I found this in my log:
>
> (II) [KMS] drm report modesetting isn't supported.
>
> I'm willing to test any patch, any release, anything, whatever you do to
> improve support for my card. I can even code with some guidance. Thanks
> in advance.

I suspect you are hitting getting a race when the drm is loaded.  Boot
into text mode and manually load the radeon modules with modesetting
enabled:
sudo modprobe radeon modeset=1
then start X:
sudo /etc/init.d/gdm start

If that doesn't work, file a bug:
https://bugs.freedesktop.org
and attach your xorg log, config and dmesg.

Alex