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

[Daniel Vetter]

On Mon, Jul 11, 2022 at 11:12:51AM +0200, Sam Ravnborg wrote:
> Hi Thomas,
> 
> On Mon, Jul 11, 2022 at 10:50:00AM +0200, Thomas Zimmermann wrote:
> > Hi
> > 
> > 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.
> > > > 
> > > > Overview:
> > > >    - Patch 1 introduces a helper, to be used by later patches in the
> > > >      series,
> > > >    - 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.
> 
> Sorry for being too enthusiastic on this one.
> Will wait a bit more in the future for these kind of patches.

Took me a bit longer to unburry and get to this, and lgtm except patch 1
where I have a semantic concern. Can you pls do the quick patch to adjust
that? Since this is all about the Cx/Rx/Dx formats I don't think it'll
matter really.

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch