Re: [PATCH 2/2] [media] Input: synaptics-rmi4: disallow impossible configuration

[Nick Dyer]

On Mon, Sep 12, 2016 at 05:30:33PM +0200, Arnd Bergmann wrote:
> The newly added debug mode for the synaptics-rmi4 driver relies on
> the v4l2 interface and vb2_vmalloc, but those might be configured
> as loadable modules when the driver itself is built-in, resulting
> in a link failure:
> 
> drivers/input/rmi4/rmi_core.o: In function `rmi_f54_remove':
> rmi_f54.c:(.text.rmi_f54_remove+0x14): undefined reference to `video_unregister_device'
> rmi_f54.c:(.text.rmi_f54_remove+0x20): undefined reference to `v4l2_device_unregister'
> drivers/input/rmi4/rmi_core.o: In function `rmi_f54_vidioc_s_input':
> rmi_f54.c:(.text.rmi_f54_vidioc_s_input+0x10): undefined reference to `video_devdata'
> drivers/input/rmi4/rmi_core.o: In function `rmi_f54_vidioc_g_input':
> rmi_f54.c:(.text.rmi_f54_vidioc_g_input+0x10): undefined reference to `video_devdata'
> drivers/input/rmi4/rmi_core.o: In function `rmi_f54_vidioc_fmt':
> rmi_f54.c:(.text.rmi_f54_vidioc_fmt+0x10): undefined reference to `video_devdata'
> drivers/input/rmi4/rmi_core.o: In function `rmi_f54_vidioc_enum_input':
> rmi_f54.c:(.text.rmi_f54_vidioc_enum_input+0x10): undefined reference to `video_devdata'
> drivers/input/rmi4/rmi_core.o: In function `rmi_f54_vidioc_querycap':
> ...
> 
> The best workaround I could come up with is to disallow the debug
> mode unless it's actually possible to call it.
> 
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Fixes: 3a762dbd5347 ("[media] Input: synaptics-rmi4 - add support for F54 diagnostics")

Acked-by: Nick Dyer <nick@xxxxxxxxxxxxx>

> ---
>  drivers/input/rmi4/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/input/rmi4/Kconfig b/drivers/input/rmi4/Kconfig
> index f3418b65eb41..4c8a55857e00 100644
> --- a/drivers/input/rmi4/Kconfig
> +++ b/drivers/input/rmi4/Kconfig
> @@ -65,7 +65,7 @@ config RMI4_F30
>  config RMI4_F54
>  	bool "RMI4 Function 54 (Analog diagnostics)"
>  	depends on RMI4_CORE
> -	depends on VIDEO_V4L2
> +	depends on VIDEO_V4L2=y || (RMI4_CORE=m && VIDEO_V4L2=m)
>  	select VIDEOBUF2_VMALLOC
>  	help
>  	  Say Y here if you want to add support for RMI4 function 54
> -- 
> 2.9.0
>