drm/radeon: white screen after X does modeswitch from KMS con

[Alex Deucher]

On Mon, Feb 13, 2012 at 9:29 PM, Jan Engelhardt <jengelh at medozas.de> wrote:
> Hello,
>
>
> the SONY PCG U3 device has a
>
> 00:0c.0 VGA compatible controller [0300]: ATI Technologies Inc Radeon
> Mobility M6 LY [1002:4c59]
>
> graphics card. With linux 3.1.10, X.org server 7.6_1.10.4 and
> xf86-video-ati-6.14.2, switching from KMS'd console to X on tty7
> yields a white screen that also stays when attempting to back to
> tty1.
>
> I have to boot with nomodeset to get a usable Xorg picture.
> Is it just that radeon_drv does not work together with KMS?

It should work fine.  Does it work any better with a newer kernel?  Is
this a regression?  If so, what was the last kernel that was working
properly? Please file a bug:
https://bugs.freedesktop.org
and attach your xorg log and dmesg output.

Alex