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Date:   Tue, 21 Aug 2018 17:44:17 +0100
From:   Brian Starkey <brian.starkey@arm.com>
To:     Matthew Wilcox <willy@infradead.org>
Cc:     dri-devel@lists.freedesktop.org, daniel.vetter@ffwll.ch,
        airlied@linux.ie, gustavo@padovan.org,
        maarten.lankhorst@linux.intel.com, seanpaul@chromium.org,
        corbet@lwn.net, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, alexandru-cosmin.gheorghe@arm.com,
        liviu.dudau@arm.com, ayan.halder@arm.com
Subject: Re: [PATCH] drm/fourcc: Add DOC: overview comment
Message-ID: <20180821164416.GA11553@e107564-lin.cambridge.arm.com>
References: <20180821161611.10424-1-brian.starkey@arm.com>
 <20180821162639.GA21697@bombadil.infradead.org>
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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