Re: [PATCH] media: i2c: select V4L2_ASYNC where needed

[Randy Dunlap]

On 9/20/21 2:58 AM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> I came across a link failure from randconfig builds:
>
> x86_64-linux-ld: drivers/media/i2c/ths8200.o: in function `ths8200_remove':
> ths8200.c:(.text+0x491): undefined reference to `v4l2_async_unregister_subdev'
> x86_64-linux-ld: drivers/media/i2c/ths8200.o: in function `ths8200_probe':
> ths8200.c:(.text+0xe49): undefined reference to `v4l2_async_register_subdev'

ths8200 is already fixed.

> x86_64-linux-ld: drivers/media/i2c/tw9910.o: in function `tw9910_remove':
> tw9910.c:(.text+0x467): undefined reference to `v4l2_async_unregister_subdev'
> x86_64-linux-ld: drivers/media/i2c/tw9910.o: in function `tw9910_probe':
> tw9910.c:(.text+0x1123): undefined reference to `v4l2_async_register_subdev'
>
> These clearly lack a 'select' statement, but I don't know why
> this started happening only now. I had a bit of a look around to find
> other configs that have the same problem, but could not come up with
> a reliable way and found nothing else through experimentation.
> It is likely that other symbols like these exist that need an extra
> select.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>   drivers/media/i2c/Kconfig | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 08feb3e8c1bf..d49eecc4fe33 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -450,6 +450,7 @@ config VIDEO_TW9906
>   config VIDEO_TW9910
>   	tristate "Techwell TW9910 video decoder"
>   	depends on VIDEO_V4L2 && I2C
> +	select V4L2_ASYNC
>   	help
>   	  Support for Techwell TW9910 NTSC/PAL/SECAM video decoder.
>   
> @@ -597,6 +598,7 @@ config VIDEO_AK881X
>   config VIDEO_THS8200
>   	tristate "Texas Instruments THS8200 video encoder"
>   	depends on VIDEO_V4L2 && I2C
> +	select V4L2_ASYNC
>   	help
>   	  Support for the Texas Instruments THS8200 video encoder.
>   

Thanks.
--
~Randy