DRI3 WSEGL plugin for TI SGX

[Merlijn Wajer]

Hi!

On 16/04/18 16:49, Tomi Valkeinen wrote:
> Hi All,
> 
> I have implemented a WSEGL plugin library for Imagination's PVR driver
> for SGX, which allows using SGX via DRI3. In other words, it is one
> piece in the puzzle of using SGX with X11.
> 
> The project is not production quality, as I have not had time to perfect
> it (and, to be honest, I'm not exactly an expert on X), but now that I
> finally got all the permissions to publish it, I'm doing just that to
> allow other people to use it and help making it fully usable.
> 
> You can find the code and a more detailed description here:
> 
> https://github.com/TexasInstruments/dri3wsegl
> 
> Hopefully with this code now public, we can get an SGX and GC320
> accelerated X11 on TI devices.

Great, this will be fun to try.

>From the README:

> Xorg's modesetting driver supports DRI3, but unfortunately only when using Glamor, which uses OpenGL for 2D acceleration. There's no OpenGL HW on TI's devices.
> 
> However, for testing purposes, it is possible to use Mesa SW rendering to fulfill the OpenGL requirement. With this this setup, SGX is used to render to a buffer, passed to the modesetting driver via DRI3, which is then composited to the screen using OpenGL SW rendering. Needless to say, the composition is very slow.
> 
> Although slow with SW rendering, modesetting driver is quite stable and the DRI3 support works fine, so it is good for testing.

There is this:

https://cgit.freedesktop.org/xorg/xserver/commit/?id=c36f56808ffbefc4a3dcf61dfad17f62aeb8e16c
https://cgit.freedesktop.org/xorg/xserver/log/glamor?id=c36f56808ffbefc4a3dcf61dfad17f62aeb8e16c
https://www.phoronix.com/scan.php?page=news_item&px=GLAMOR-GLES2-Fallback
https://cgit.freedesktop.org/xorg/xserver/tree/glamor/glamor_egl.c#n952

So actually, Glamor should already work, given a new enough X server?

This will be exciting to try out on the N900 and perhaps on the Droid 4
as well. I will try to test this in a few weeks from now. I would
personally be very happy if we can use just the modesetting driver.

On a related note, maemo leste also did some work on this for DRI2:
https://github.com/freemangordon/pvr

I think this works as a drop-in replacement on Fremantle for
pvrPVR2D_DRI2WSEGL, and can also work with newer X versions. But
dri3wsegl seems like the proper way forward here.

Cheers,
Merlijn