Re: [PATCH 7/7] [media] go7007: add MEDIA_CAMERA_SUPPORT dependency

[Mauro Carvalho Chehab]

Em Tue, 26 Jan 2016 15:10:01 +0100
Arnd Bergmann <arnd@xxxxxxxx> escreveu:

> If MEDIA_SUBDRV_AUTOSELECT and VIDEO_GO7007 are both set, we
> automatically select VIDEO_OV7640, but that depends on MEDIA_CAMERA_SUPPORT,
> so we get a Kconfig warning if that is disabled:
> 
> warning: (VIDEO_GO7007) selects VIDEO_OV7640 which has unmet direct dependencies (MEDIA_SUPPORT && I2C && VIDEO_V4L2 && MEDIA_CAMERA_SUPPORT)
> 
> This adds another dependency so we don't accidentally select
> it when it is unavailable.

This is another bogus warning.

The MEDIA_foo_SUPPORT actually controls what drivers are visible,
but it doesn't enable any driver. They just control the visibility
of the drivers, and the APIs that will be enabled (V4L2 and/or DVB).

The aim of MEDIA_foo_SUPPORT is to make life easier to end users,
making easier for them to filter the drivers that they may need.

If one selects MEDIA_VIDEO_SUPPORT, the V4L2 API (and V4L core) will be 
enabled, and all drivers that support a camera should appear at the 
menu, including drivers that *also* support other features (like TV
and/or stream support).

That's the case of go7007.

That has nothing to do with the features selection for such driver.

Once go7007 driver is selected, if MEDIA_SUBDRV_AUTOSELECT, all
i2c drivers that cope together with go7007 are selected, making the
driver to fully support all devices it knows.

Advanced users may unselect MEDIA_SUBDRV_AUTOSELECT and add there just
the I2C driver(s) it needs for his specific hardware.

Despite the warning, the Kconfig will do the right thing, not
allowing invalid configurations.

Regards,
Mauro


> 
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>  drivers/media/usb/go7007/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/usb/go7007/Kconfig b/drivers/media/usb/go7007/Kconfig
> index 95a3af644a92..af1d02430931 100644
> --- a/drivers/media/usb/go7007/Kconfig
> +++ b/drivers/media/usb/go7007/Kconfig
> @@ -11,7 +11,7 @@ config VIDEO_GO7007
>  	select VIDEO_TW2804 if MEDIA_SUBDRV_AUTOSELECT
>  	select VIDEO_TW9903 if MEDIA_SUBDRV_AUTOSELECT
>  	select VIDEO_TW9906 if MEDIA_SUBDRV_AUTOSELECT
> -	select VIDEO_OV7640 if MEDIA_SUBDRV_AUTOSELECT
> +	select VIDEO_OV7640 if MEDIA_SUBDRV_AUTOSELECT && MEDIA_CAMERA_SUPPORT
>  	select VIDEO_UDA1342 if MEDIA_SUBDRV_AUTOSELECT
>  	---help---
>  	  This is a video4linux driver for the WIS GO7007 MPEG