Hi Am 06.11.21 um 22:02 schrieb Sven Schnelle:
Thomas Zimmermann <tzimmermann@xxxxxxx> writes:Hi Am 01.11.21 um 09:54 schrieb Sven Schnelle:Hi Thomas, Thomas Zimmermann <tzimmermann@xxxxxxx> 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,
Cool!
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.
Don't worry. As I outlined , you can still convert any image from XRGB888 to RGB332 and display this instead.
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?
Simply call drm_fbdev_generic_setup() after registering the device. This should give you a console.
Don't bother about HW-accelerated blitting. From what I've heard, it barely makes a difference nowadays. And our generic helpers have plenty of features. Not using them to get a small benefit from HW blitting isn't worth it.
Best regards Thomas
Thanks Sven
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Ivo Totev
Attachment:
OpenPGP_signature
Description: OpenPGP digital signature
