Re: [PATCH] drm/pl111: Advertise no pixel blending

[Linus Walleij]

On Wed, Sep 9, 2026 at 10:16 AM Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:

> > The PL110/PL111 controller scans out a single framebuffer and does not
> > blend its alpha channel with a background. Advertise
> > DRM_MODE_BLEND_PIXEL_NONE to match the existing hardware behavior.
>
> Why does the driver report ARGB formats in the first place. I'm looking
> at the code at [1] and I don't see any difference to XRGB. Unless I'm
> missing something, please remove ARGB formats from this driver instead.
> Drivers should not report formats they don't support.

This should be the TRM for PL111:
https://support.arm.com/documentation/ddi0293/c/?lang=en

I checked it and indeed the ARGB* should be search/replaced with
XRGB everywhere.

Shall I propose a patch?

I also have the actual hardware so I can test it properly.

Yours,
Linus Walleij