Re: Confusion in usr/include/linux/videodev.h

[Jaswinder Singh Rajput <jaswinderlinux@gmail.com>]

On Wed, Jan 21, 2009 at 2:24 PM, Trent Piepho <xyzzy@speakeasy.org> wrote:
> On Wed, 21 Jan 2009, Jaswinder Singh Rajput wrote:
>> On Wed, Jan 21, 2009 at 7:20 AM, Mauro Carvalho Chehab
>> <mchehab@infradead.org> wrote:
>> > On Wed, 21 Jan 2009 07:10:38 +0530
>> > Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:
>> >
>> >> usr/include/linux/videodev.h is giving 2 warnings in 'make headers_check':
>> >>  usr/include/linux/videodev.h:19: leaks CONFIG_VIDEO to userspace where it is not valid
>> >>  usr/include/linux/videodev.h:314: leaks CONFIG_VIDEO to userspace where it is not valid
>> >>
>> >> Whole file is covered with #if defined(CONFIG_VIDEO_V4L1_COMPAT) || !defined (__KERNEL__)
>> >>
>> >> It means this file is only valid for kernel mode if CONFIG_VIDEO_V4L1_COMPAT is defined but in user mode it is always valid.
>> >
>> > V4L1 is the old deprecated userspace API for video devices. It is still
>> > required by some userspace applications. So, on userspace, it should be
>> > included. Also, this allows that one userspace app to be compatible with both
>> > V4L2 API (the current one) and the legacy V4L1 one.
>> >
>> > It should be noticed that are still a few drivers using the legacy API yet to
>> > be converted.
>> >
>>
>> If you have no objections then I will make a patchset which do followings:
>> 1. Remove  #if defined(CONFIG_VIDEO_V4L1_COMPAT) || !defined
>> (__KERNEL__) from include/linux/videodev.h
>> 2. cover all #include <linux/videodev.h> with #ifdef
>> CONFIG_VIDEO_V4L1_COMPAT in kernel
>>
>> By this way, we can satisfy both kernel space and userspace issue and
>> also get rid of above warnings.
>>
>> If you have better suggestion then let me know.
>
> That sounds like it will add a mess of #if's.  How about this?
>
> diff -r 29c5787efcda linux/include/linux/videodev.h
> --- a/linux/include/linux/videodev.h    Thu Jan 15 09:07:03 2009 -0800
> +++ b/linux/include/linux/videodev.h    Wed Jan 21 00:51:45 2009 -0800
> @@ -15,7 +15,8 @@
>  #include <linux/ioctl.h>
>  #include <linux/videodev2.h>
>
> -#if defined(CONFIG_VIDEO_V4L1_COMPAT) || !defined (__KERNEL__)
> +#if (defined(__KERNEL__) && defined(CONFIG_VIDEO_V4L1_COMPAT)) \
> +    || !defined (__KERNEL__)
>
>  #define VID_TYPE_CAPTURE       1       /* Can capture */
>  #define VID_TYPE_TUNER         2       /* Can tune */
>
> Now CONFIG_VIDEO_V4L1_COMPAT will only be used in the kernel.
>

No, this will still give warnings.

Please run 'make headers_check'

--
JSR