Re: [build bug] uvc_status_cleanup(): undefined reference to `input_unregister_device'

[Laurent Pinchart <laurent.pinchart@skynet.be>]

Hi Mauro,

On Wednesday 11 February 2009 09:29:33 Mauro Carvalho Chehab wrote:
> On Tue, 10 Feb 2009 01:44:22 +0100
>
> Laurent Pinchart <laurent.pinchart@skynet.be> wrote:
> >
> > I'm not completely satisfied with this though, as the
> > USB_VIDEO_CLASS_INPUT_EVDEV completely disappears from the configuration
> > menu if INPUT is set to 'm' and USB_VIDEO_CLASS to 'y'. Being no Kconfig
> > guru, I'd appreciate if someone could help me to find a nicer fix (if
> > that's possible at all).
>
> This doesn't seem to be right. You're just disabling INPUT, if CONFIG_INPUT
> = m and USB_VIDEO_CLASS=y. You should, instead, force USB_VIDEO_CLASS to be
> 'm' or 'n' on such case.
>
> IMO, a better approach would be the one on the patch bellow.
>
> Cheers,
> Mauro
>
> Fix input dependencies on uvc driver
>
> As reported by Ingo:
> -tip testing found that certain (user-reachable) Kconfig combinations
> can cause this build failure on latest mainline:
>
>  drivers/built-in.o: In function `uvc_status_cleanup':
>   (.text+0x221cca): undefined reference to `input_unregister_device'
>   drivers/built-in.o: In function `uvc_status_init':
>   (.text+0x221d4c): undefined reference to `input_allocate_device'
>   drivers/built-in.o: In function `uvc_status_init':
>   (.text+0x221db3): undefined reference to `input_free_device'
>   drivers/built-in.o: In function `uvc_status_init':
>   (.text+0x221ec6): undefined reference to `input_register_device'
>   drivers/built-in.o: In function `uvc_status_complete':
>   uvc_status.c:(.text+0x2222ec): undefined reference to `input_event'
>
> triggered on v2.6.29-rc3-697-gae1a25d. The problem is this combination:
>
>   CONFIG_INPUT=m
>   CONFIG_USB_VIDEO_CLASS=y
>   CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV=y
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
>
> diff --git a/drivers/media/video/uvc/Kconfig
> b/drivers/media/video/uvc/Kconfig index c2d9760..fab4733 100644
> --- a/drivers/media/video/uvc/Kconfig
> +++ b/drivers/media/video/uvc/Kconfig
> @@ -1,5 +1,6 @@
>  config USB_VIDEO_CLASS
>  	tristate "USB Video Class (UVC)"
> +	depends on !USB_VIDEO_CLASS_INPUT_EVDEV || INPUT
>  	---help---
>  	  Support for the USB Video Class (UVC).  Currently only video
>  	  input devices, such as webcams, are supported.
> @@ -9,7 +10,7 @@ config USB_VIDEO_CLASS
>  config USB_VIDEO_CLASS_INPUT_EVDEV
>  	bool "UVC input events device support"
>  	default y
> -	depends on USB_VIDEO_CLASS && INPUT
> +	depends on INPUT
>  	---help---
>  	  This option makes USB Video Class devices register an input device
>  	  to report button events.

That's even worse. The following configurations would then be valid

INPUT = m/y
USB_VIDEO_CLASS = n
USB_VIDEO_CLASS_INPUT_EVDEV = m/y

USB_VIDEO_CLASS_INPUT_EVDEV must depend on USB_VIDEO_CLASS to be displayed as 
a child of USB_VIDEO_CLASS in the configuration menu.

Regards,

Laurent Pinchart