Re: [PATCH v3 00/10] drm: Add support for low-color frame buffer formats

From: Thomas Zimmermann
Date: Mon Jul 11 2022 - 04:50:06 EST


Am 09.07.22 um 15:38 schrieb Sam Ravnborg:
Hi Geert,

On Fri, Jul 08, 2022 at 08:20:45PM +0200, Geert Uytterhoeven wrote:
Hi all,

A long outstanding issue with the DRM subsystem has been the lack of
support for low-color displays, as used typically on older desktop
systems, and on small embedded displays.

For the patchset

Acked-by: Thomas Zimemrmann <tzimmermann@xxxxxxx>

IT is super to have this addressed - thanks!

This patch series adds support for color-indexed frame buffer formats
with 2, 4, and 16 colors. It has been tested on ARAnyM using a
work-in-progress Atari DRM driver supporting 2, 4, 16, 256, and 65536
colors, with text console operation, fbtest, and modetest.

- Patch 1 introduces a helper, to be used by later patches in the
- Patch 2 introduces a flag to indicate color-indexed formats,
- Patches 3 and 4 correct calculations of bits per pixel for sub-byte
pixel formats,
- Patches 5 and 6 introduce the new C[124] formats,
- Patch 7 fixes an untested code path,
- Patch 8 documents the use of "red" for light-on-dark displays,
- Patches 9 and 10 add more fourcc codes for light-on-dark and
dark-on-light frame buffer formats, which may be useful for e.g. the
ssd130x and repaper drivers.

Applied all patches to drm-misc (drm-misc-next), including the last two
RFC patches as we then have the formats ready when a user pops up.

I know it's v3 already, but give people at least a workday for reviewing before merging patches of this size and impact. Friday-evening patches are not supposed to be merged on Saturday afternoons.

Best regards


Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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