Thomas Zimmermann tzimmermann@suse.de writes:
Hi
Am 01.11.21 um 09:54 schrieb Sven Schnelle:
Hi Thomas, 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. Don't worry, it's easy. Take a look at the cirrus driver for a simple DRM driver. [1]
I have converted the driver, but am using FORMAT_C8 because i haven't figured out yet how to switch the card to XRGB8888. That's still on the TODO list.
One question about hw blitting: with the old fbdev framework one could replace the fb_imageblit function. For normal console text, this function gets called with a monochrome bitmap, and an fg/bg color value. This makes it easy to use HW accelerated blitting for text. In the gpu/drm drivers i think i found only one driver (nouveau) doing this and that was via the drm fbdev layer.
Is that still the way to go, or is there a better way to do HW accelerated text blitting?
Thanks Sven