radeon problems with current cvs code

[Luca Dionisi]

On 3/25/06, Benjamin Herrenschmidt <benh at kernel.crashing.org> wrote:
> On Sat, 2006-03-25 at 02:26 +0100, Luca Dionisi wrote:
> > I'm having problems with Xorg built from cvs sources very recently.
> > I've also built from cvs sources libdrm and the latest kernel (2.6.16)
> > with the drm enabled for my card (radeon)
> > I don't know for sure, but I think my problem is with the
> > video driver (the ati open source driver)
> > The syptom is that Xorg start, but sometimes it hangs hup very
> > quickly, sometimes when I change VT, sometimes when I
> > click the mouse, ... Most of the times my whole machine
> > becomes unusable.
> >
> > Any help please! I attach the log and the xorg.conf
>
> Looks like the engine is going nuts. Can you try:
>
>  - Disabling AGP fast write
>  - Lowering AGP speed
>  - Load DRM with option no_wb=1
>  - Try latest DRM CVS
>
> And tell me if any of these helps. Also, when you say "very recently"
> for your X.org build, when exactly did you get the ati driver from CVS ?
> If it was more than 4 days ago, it might be worth updating and trying
> again.
>
> Ben.
>
>
>

Very recently was not enough recently.
I updated again from cvs and now it all works.

Just 2 questions:
> Load DRM with option no_wb=1
what is it for and how do I do it?
> Try latest DRM CVS
I have kernel 2.6.16. I saw that source files such as radeon.c
were identical to the ones in DRM CVS. Am I wrong?
At the moment I have a kernel compiled without module support.
And the radeon drm is built-in. Do I have to change that?

At the moment it works, but xgl is slow with movies.
I saw this sentence in the suse site:

Driver has neither pBuffer nor FBO support. When using a composite
manager all windows are rendered in software and only compositing is
hardware accelerated. Astonishingly, this works well enough for most
use cases.

What does it mean? That is, is the driver _never_ going to have that support?

Many thanks

--Luca