Bug#569332: xserver-xorg-video-radeon: KMS/UMS confusion and hangup if radeon.ko was not loaded before starting X

[Luca Tettamanti]

On Thu, Feb 11, 2010 at 3:13 PM, Piotr Engelking <inkerman42 at gmail.com> wrote:
> Package: xserver-xorg-video-radeon
> Version: 1:6.12.99+git20100201.a887818f-1
> Severity: important
>
> With upstream kernel 2.6.33-rc7, starting X while the KMS-enabled
> 'radeon' kernel module is not loaded yet results in the kernel using
> KMS and the X server using UMS. Pressing Ctrl+Alt+F1 while in X results
> in hangup: the monitor stops receiving video signal and the X server
> stops reacting to keypresses. Killing the X server restores the console
> to an usable state.

The problem is known, there's also a proposed patch floating around
[1]; as a workaround you can add radeon to /etc/modules so that it's
loaded at boot.
Might be tagged as duplicate of #569098...

Luca
[1] http://permalink.gmane.org/gmane.comp.freedesktop.xorg.drivers.ati/12853