[Intel-gfx] GMA 500 Support

[Ben Gamari]

The following is my own uninformed opinion. It is not to be taken as
fact, the opinion of Intel, or anyone associated with them.

On Sat, Sep 26, 2009 at 03:39:53PM -0500, David A. Greene wrote:
> I am interested in getting the GMA 500 (Pouslbo) chipset working in Linux.
> I've done some small investigating into the (unmaintained) Ubuntu driver.
> I believe this should get integrated with the intel-gfx effort and be an
> officially supported driver.

This doesn't seem like this would make too much sense. The driver at least
doesn't belong in xv86-video-intel. For one, it seems that something
went horribly wrong in the writing of the psb driver. There is horrible
code duplication in the driver and no one has been keeping it up-to-date
with the recent changes in the stack.

Moreover, the GMA500 hardware is a completely different design from the
other GMA products.  The core itself was licensed from a third-party IP
core company (a derivative of the PowerVR SGX design from Imagination
Technologies). It doesn't look like Imagination is going to release
documentation or even a reasonable driver unless someone with power
(e.g. Intel or Dell) demands it of them.

Honestly, I doubt that this will happen. I'm certain that there are
endless IP issues with the PowerVR core and thus it is unlikely that
they will ever be able to release adequate documentation.  The best
situation I am hoping for is to realize they made a mistake in selecting
PowerVR and use their own design in future platform iterations. Linux
has a very good chance in the netbook market; it would be a horrible
shame to see this opportunity slip by because of a lack of usable
embedded GPU.

I hope that I am wrong about the above. From what I can see, the SGX
design is a pretty powerful platform and it would take a substantial
amount of work for Intel to develop a similarly low-power chip, even if
they were to start with an existing design. Moreover, the SGX core is
used in countless embedded applications. By implementing a Poulsbo
driver, we should get much of the support for the SGX core for free.

> 
> What's the best way to get started.  Right now I'm hacking the Debian
> unstable sources, trying to integrate the Ubuntu driver in there.  
> Unfortunately, the Ubuntu driver seems quite stale (doesn't use GEM,
> etc.) and so the going is rough.
> 
> Any documentation on the GMA 500 I can look at?  I don't care about
> 3D yet.  Getting decent 2D performance is the first step.

I'm almost certain that there (unfortunately) is no documentation
available for this chip. If there were, I'm sure we would be farther
along in supporting it. Even the folks in the Intel Linux graphics group
do not have access to the documentation.

Anyways, let's all hope this mess is resolved before long. Please
correct me if I got anything wrong above; I try to stay informed but
sometimes I miss things.

- Ben