Re: [PATCH] drm/fourcc: Add DOC: overview comment

[Brian Starkey]

Hi Matthew,

On Tue, Aug 21, 2018 at 09:26:39AM -0700, Matthew Wilcox wrote:
> On Tue, Aug 21, 2018 at 05:16:11PM +0100, Brian Starkey wrote:
> > There's a number of things which haven't previously been documented
> > around the usage of format modifiers. Capture the current
> > understanding in an overview comment and add it to the rst
> > documentation.
> >
> > Ideally, the generated documentation would also include documentation
> > of all of the #defines, but the kernel-doc system doesn't currently
> > support kernel-doc comments on #define constants.
>
> Can you turn them into enums?  This seems to work ok:
>
> -/* color index */
> -#define DRM_FORMAT_C8          fourcc_code('C', '8', ' ', ' ') /* [7:0] C */
> -
> -/* 8 bpp Red */
> -#define DRM_FORMAT_R8          fourcc_code('R', '8', ' ', ' ') /* [7:0] R */
> +enum {
> +       /* color index */
> +       DRM_FORMAT_C8   = fourcc_code('C', '8', ' ', ' '), /* [7:0] C */
> +       /* 8 bpp Red */
> +       DRM_FORMAT_R8   = fourcc_code('R', '8', ' ', ' '), /* [7:0] R */
> +};
>
> but I appreciate this is user API and maybe there's some code out there
> that does #ifndef DRM_FORMAT_C8 ...

Thanks for the suggestion, Daniel did mention the same. However,
unfortunately I don't think we can safely change the UAPI header in
this manner.

Cheers,
-Brian