On Mon, Aug 13, 2018 at 05:55:25PM +0200, Takashi Iwai wrote:
> On Mon, 13 Aug 2018 17:46:51 +0200, Dmitry V. Levin wrote:
> > 
> > Replace NULL with 0 in uac_mixer_unit_bmControls() to fix the following
> > linux/usb/audio.h userspace compilation error:
> > 
> > /usr/include/linux/usb/audio.h: In function 'uac_mixer_unit_bmControls':
> > /usr/include/linux/usb/audio.h:304:10: error: 'NULL' undeclared (first use in this function)
> >    return NULL;
> > 
> > Fixes: 6cfd839ae78e ("ALSA: usb-audio: UAC3. Add support for mixer unit.")
> > Cc: <stable@vger.kernel.org> # v4.18
> > Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
> 
> Hrm, can we include the standard header for definition of NULL
> instead?  It's way too ugly to use 0 just for that.

It's fine to return 0 as a null pointer.  If you prefer NULL,
please include a header that won't break userspace,
or just move the function out of UAPI.

Thanks,


-- 
ldv