Hi
Am 01.11.21 um 09:54 schrieb Sven Schnelle:
Hi Thomas,
Thomas Zimmermann tzimmermann@suse.de writes:
Am 31.10.21 um 20:53 schrieb Sven Schnelle:
Hi List(s), i wrote a fbdev driver for the HP Visualize FX cards used some of the PA-RISC workstations. It utilizes some of the 2D acceleration features present in the card. [..]
Thanks for all the work you put into this. We welcome drivers even for older hardware, but not for fbdev. DRM is all the rage now and has been for a while. I'd like to ask you to convert the driver to DRM and resubmit to dri-devel@lists.freedesktop.org.
I while ago, I made conversion helpers for this. You can look at [1] for a trivial DRM drivers that wraps existing fbdev drivers for use with DRM. Once you have that, it turns into a refactoring job.
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. Don't worry, it's easy. Take a look at the cirrus driver for a simple DRM driver. [1]
If you need help, there's dri-devel@lists.freedesktop.org.
Best regards Thomas
[1] https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/tiny/cirrus.c
Sven