Re: [PATCH 1/7] drm/fourcc: Add R8 to drm_format_info

[Daniel Vetter <daniel@ffwll.ch>]

On Tue, Aug 17, 2021 at 03:59:56PM +0200, Daniel Vetter wrote:
> On Tue, Aug 17, 2021 at 02:29:11PM +0200, Noralf Trønnes wrote:
> > Add an entry in drm_format_info for the existing format DRM_FORMAT_R8.
> > 
> > Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
> > ---
> >  drivers/gpu/drm/drm_fourcc.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> > index eda832f9200d..783844bfecc1 100644
> > --- a/drivers/gpu/drm/drm_fourcc.c
> > +++ b/drivers/gpu/drm/drm_fourcc.c
> > @@ -133,6 +133,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
> >  {
> >  	static const struct drm_format_info formats[] = {
> >  		{ .format = DRM_FORMAT_C8,		.depth = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 },
> > +		{ .format = DRM_FORMAT_R8,		.depth = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 },
> 
> Uh the depth = 0 on these is all a big lie, same for the 332 formats
> below. The only format which is officially depth = 8 is the C8 one. I'm
> not sure it's a great idea to announce others as depth = 8 ...

btw if you really want to go fancy, full dithering for these might not be
a complete waste of effort to type it. Temporal dithering probably too
tricky, and also too many folks don't like that.
-Daniel

> 
> Might be good to throw a patch on top to drop these. Same for the ARGB1555
> ones and it's permutations.
> 
> Anyway it's consistent with what's there.
> 
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> >  		{ .format = DRM_FORMAT_RGB332,		.depth = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 },
> >  		{ .format = DRM_FORMAT_BGR233,		.depth = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 },
> >  		{ .format = DRM_FORMAT_XRGB4444,	.depth = 0,  .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
> > -- 
> > 2.32.0
> > 
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

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