What to do now after Xgl and Xegl are gone....

[Kalle Vahlman]

2009/6/16 Corbin Simpson <mostawesomedude at gmail.com>:
> On 06/16/2009 11:26 AM, Soeren Sandmann wrote:
>> Adam Jackson<ajax at nwnk.net>  writes:
>>
>>> On Tue, 2009-06-16 at 11:32 +0200, david at protonic.nl wrote:
>>>
>>>>> You probably want to start with something like the Xorg fbdev driver and
>>>>> then start bolting on acceleration paths that call down into the EGL
>>>>> driver.  Getting that to interact well with GLX clients should be
>>>>> entertaining.
>>>> I was suspecting something like that.... Isn't there anybody else who has done
>>>> this before? How do the folks from Maemo do this?
>>> Xomap is findable in the maemo sources somewhere, I believe.  I used to
>>> have a URL for it but it seems to no longer work.  It's a kdrive server.
>>> I don't think it uses the hardware GL support at all though.
>>
>> There is also this an xf86-video-omapfb driver:
>>
>>          http://cgit.pingu.fi/xf86-video-omapfb/
>>
>> I don't know anything about it, though.
>
> But I do. :3
>
> xf86-video-omapfb is just fbdev with a bit of hax to make Xv be
> semi-accelerated through the DSP. It's still massive amounts of fail.

x-v-o doesn't touch the DSP, it uses the (OMAP internal or external in
the case of N8x0) display controller to do hw-accelerated colorspace
conversion and scaling.

If by fail you meant lack of 2D acceleration, well that's correct,
there isn't any available AFAIK (when strictly speaking of OMAP
without the often bundled license-encumbered graphics chips).

> IMO the correct answer is to port OMAP DSS2 to true KMS, and then add an
> SGX Gallium driver to make the SGX 3D core do acceleration, but that's a
> long ways off. (Unless anybody's working on SGX reverse-engineering, but
> my search so far has not indicated any progress on that front.)

Nokia took a whack at it and I hear they backed it out due to it
turning out to be hardware deceleration. Not sure if that means that
the SGX core is unsuitable for the acceleration or just the interface
to it though...

> As far as using the SGX/TI blob for acceleration, we only say, "Good
> luck." :3

...and this being the only way to use it, I don't see anyone finding
it out either.

For embedded devices lacking good or available gfx chip, other ways of
using the hardware better in rendering might be more worthwhile things
to investigate:

  http://sandbox.movial.com/blog/2009/06/pixman-gets-neon-support/

-- 
Kalle Vahlman, zuh at iki.fi
Powered by http://movial.com
Interesting stuff at http://sandbox.movial.com
See also http://syslog.movial.fi