Re: [PATCH/RFT] fbdev driver for HP Visualize FX cards

[Sven Schnelle <svens@stackframe.org>]

Hi Thomas,

Thomas Zimmermann <tzimmermann@suse.de> writes:

> Am 01.11.21 um 09:54 schrieb Sven Schnelle:
>> Thomas Zimmermann <tzimmermann@suse.de> writes:
>> Thanks, i wasn't aware as i normally don't do any graphics related
>> development. I take a look at dri and port the driver, which is
>> hopefully not too hard.
>
> Sounds good.
>
> The one big difference when converting is that DRM really wants
> drivers to support 32-bit XRGB colors. It's not a DRM limitation per
> se, but a requirement of today's userspace programs. AFAICS your fbdev
> driver uses a 256-color palette format. So the DRM driver would have
> to convert
> XRGB8888 to 8-bit RGB332 and install a corresponding palette.

Right now the driver only supports 8 bit pseudocolor, because i wanted
to start with something easy to get the kernel fbcon running. I have no
idea (yet) how to switch the card into other color formats. And neither
how to do pseudo color with drm. But i'll figure it out i guess.

> Don't worry, it's easy. Take a look at the cirrus driver for a simple DRM
> driver. [1]

Great, i also picked that driver as a template. :-)

Thanks for your help and pointers, much appreciated!

Sven