Re: [PATCH v2] drm/imagination: DRM_POWERVR should depend on ARCH_K3

[Adam Ford]

On Tue, Feb 20, 2024 at 5:55 AM Erico Nunes <nunes.erico@xxxxxxxxx> wrote:
>
> Hi,
>
> On Mon, Feb 19, 2024 at 9:38 PM Adam Ford <aford173@xxxxxxxxx> wrote:
> > /usr/share/vulkan/explicit_layer.d/VkLayer_MESA_overlay.json
> > ERROR:            loader_validate_instance_extensions: Instance
> > extension VK_KHR_wayland_surface not supported by available ICDs or
> > enabled layers.
> > Failed to create Vulkan instance.
> >
> > I have tried running in X.org mode instead of Wayland, but I get a
> > different set of errors:
> >
> > [ 11102.013] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so
> > [ 11102.014] (II) Module fbdevhw: vendor="X.Org Foundation"
> > [ 11102.014]    compiled for 1.21.1.7, module version = 0.0.2
> > [ 11102.014]    ABI class: X.Org Video Driver, version 25.2
> > [ 11102.015] (II) FBDEV(0): using default device
> > [ 11102.016] (II) modeset(G0): using drv /dev/dri/card1
> > [ 11102.016] (EE)
> > Fatal server error:
> > or all framebuffer devices
> > [ 11102.016] (EE)
> > [ 11102.017] (EE)
> > Please consult the The X.Org Foundation support at http://wiki.x.org  for help.
>
>
> The wayland and xcb extensions are not really supported at the moment
> in Mesa for powervr, so this kind of use case does not really work
> yet. For a first test, indeed the Sascha Willems triangle with
> -DUSE_D2D_WSI=ON is probably best.
>
> One thing I can add is that most Wayland compositors use OpenGL for
> rendering and will only expose linux dmabuf capability if accelerated
> OpenGL support is found by the compositor. So even if you manage to
> hack some WSI functionality to be exposed by the Vulkan driver, it
> still won't work out of the box with regular compositors since there
> is no zink/OpenGL support yet. There is some experimental Vulkan
> renderer support in some compositors but last time I tried they hit
> other limitations due to the early state of powervr Vulkan in Mesa.

If I disable the GUI, do you think it would render via kms/drm?  I was
having issues starting Ubuntu with X11.

>
> I did some work related to this and managed to run a Vulkan triangle
> with Wayland and a modified compositor so far. So at least we could
> get the client side out of the way soon. But that depends on a Mesa
> development branch from Imagination which is being heavily reworked,
> so we need to wait for that rework to make its way into upstream Mesa
> before making progress on that work being upstreamed.

OK.  I won't spend any more time on it.  I knew the driver was in its
infancy, but I didn't realize how much.

I'll likely push my existing device tree changes to the Geert's
Renesas tree so the GPU node can be added which should make this
easier in the future.  I can push my tweak via gitlab, adding
DEF_CONFIG("renesas,r8a774a1-gpu", "renesas,du-r8a774a1"), if you
think that would be accepted.

adam
>
>
> Erico