Re: wayland: wrong tiling with wl_drm on Vivante GC2000

Hi Christian,

On Thu, 30 Mar 2023 at 20:15, Christian Gudrian <[email protected]> wrote:

> We're running a custom Wayland compositor based on Qt Wayland on an i.MX6
> Quad system with a Vivante GC2000 GPU using the Mesa Gallium driver. While
> the compositor itself displays correctly, client buffers are displayed with
> wrong tiling.
>
> So far I've found out, that the client's __DRIimage is created by
> etna_resource_create with a tiled layout. This image is later passed to
> create_wl_buffer which ignores the tiling information and passes the
> image's FD to wl_drm_create_prime_buffer.
>
> If I patch etna_resource_create to always use a linear layout the client's
> buffer is displayed correctly. That's certainly not how to do it correctly.
> Is there a way to ensure a linear layout for this use case?
>

You need to force QtWayland to use the wp-linux-dmabuf-v1 platform
integration for the compositor. All the others do this automatically but Qt
requires an environment variable for this.

Cheers,
Daniel