[Intel-gfx] [PATCH] Reintegrate legacy UMS.

[Chris Wilson]

On Sat, 28 Aug 2010 16:03:38 -0400, Andrew Guertin <lists at dolphinling.net> wrote:
> On 08/26/2010 01:20 PM, Chris Wilson wrote:
> > The branch is available for testing from
> >
> > http://cgit.freedesktop.org/~ickle/xf86-video-intel/log/?h=shadow
> >
> > To enable the use of the shadow, you will have to add
> >
> > Section "Device"
> >    Option "Shadow" "True"
> > EndSection
> >
> > to your xorg.conf.
> 
> I've built this (I hope correctly*), and added the configuration**, and I get 
> the following line in my Xorg.log:
> 
> [    91.311] (WW) intel(0): Option "Shadow" is not used
> 
> Is this expected?

That implies you are running the old driver. You should see a message like
"Shadow buffer allocated" instead.
 
> Also, when you say "You also lose EXA acceleration", do you mean UXA? Or am I 
> confused?

This was a reference to the acceleration that legacy/ums attempted to
still provide. With shadow all rendering, both core, Render and GL, should
be done on the CPU with only the final blit from the shadow to the scanout
being performed by the GPU. This is done to avoid reallocating entries in
the GTT and to minimise movement between memory domains.

> * What I did was modify gentoo's x11 overlay for xf86-video-intel from git, to 
> pull from http://cgit.freedesktop.org/~ickle/xf86-video-intel instead of the 
> normal place
> 
> ** After a lot of confusion, I ran Xorg -configure, cropped the Device section 
> out of its output, stuck it in xorg.conf.d, and added Option "Shadow" "True" to 
> that section

That sounds like it should have worked. You probably want to verify that
each of the steps completed successfully.

-- 
Chris Wilson, Intel Open Source Technology Centre