glxgears on Etnaviv: couldn't get an RGB, Double-buffered visual

[Alexey Brodkin]

Hi Lucas,

On Fri, 2017-11-24 at 17:11 +0100, Lucas Stach wrote:
> Hi Alexey,
> 
> Am Freitag, den 24.11.2017, 16:02 +0000 schrieb Alexey Brodkin:
> > 
> > Hello,
> > 
> > Being in the middle of bring-up of the new board with Vivante GPU (HSDK namely,
> > see https://urldefense.proofpoint.com/v2/url?u=https-3A__git.kernel.org_pub_scm_linux_kernel_git_torvalds_linux.git_tree_arch_arc_plat-2Dhsdk&d=Dw
> > IDaQ&c=DPL6_X_6JkXFx7AXWqB0tg&r=lqdeeSSEes0GFDDl656eViXO7breS55ytWkhpk5R81I&m=ZXa-564Jm43PXsqGXCf2US2DY7C0qIlCw6c56pL-
> > bLY&s=ZJSI1u6GgsRHNIcONVFfIKvn1AWaB38GmtCN1dGB3w0&e=)
> > I was looking at simple 3D test apps to see how Etnaviv works on the hardware.
> > 
> > So far I was able to get kmscube working perfectly fine and the next item I took
> > was glxgears (for some reason I was under impression that's de facto "Hello world" app
> > in the GPU world). But apparently even with Xserver up and running glxgears doesn't work.
> > 
> > Moreover I tried the same thing on Wandboard Quad but to no avail as well.
> > That's what I saw:
> > ------------------------->8---------------------
> > # glxgears
> > Error: couldn't get an RGB, Double-buffered visual
> > 
> > # glxinfo
> > name of display: :0
> > Error: couldn't find RGB GLX visual or fbconfig 
> > ------------------------->8---------------------
> > 
> > Googling didn't help here unfortunately so maybe some pointers could be
> > suggested here... like what do I do wrong and if glxgears is supposed to
> > work on top of DRM GPU at all?
> > 
> > Thanks a lot in advance!
> 
> For 3D acceleration to work under X you need the etnaviv specific DDX
> driver, which can be found here:
> 
> https://urldefense.proofpoint.com/v2/url?u=http-3A__git.arm.linux.org.uk_cgit_xf86-2Dvideo-2Darmada.git_log_-3Fh-3Dunstable-2Ddevel&d=DwIDaQ&c=DPL6_
> X_6JkXFx7AXWqB0tg&r=lqdeeSSEes0GFDDl656eViXO7breS55ytWkhpk5R81I&m=ZXa-564Jm43PXsqGXCf2US2DY7C0qIlCw6c56pL-
> bLY&s=ZzK2fxA6_XlN6pGnf2Tpo6qKzzQh76ocWZ6IDR-WPtc&e=

Thanks for the pointer, still a couple of questions below...

> Don't let you get confused by the name, the armada driver implements
> support for both armada drm and imx-drm and the etnaviv DDX. This
> provides 2D acceleration on the Vivante 2D cores, as well a the DRI2/3
> bit necessary to get a 3D context on X.

From Wandboard's .dts I see that 2D core is a separate node with separate
set of registers mapped at a different location in memory, right?

Do you know if that's possible if the same one memory-mapped register set
controls both 3D and 2D engine?

If we happen to not have 2D core if that's a no go for us for anything?
Like no compositing whatsoever etc?

In the meantime I'll try to figure out if we have 2D core or not.

-Alexey