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Date:   Tue, 5 Oct 2021 18:31:25 +0200
From:   Mauro Carvalho Chehab <mchehab@kernel.org>
To:     Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc:     <linux-media@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <yj.chiang@mediatek.com>
Subject: Re: [PATCH] media: Kconfig: Make DVB_CORE=m possible when
 MEDIA_SUPPORT=y
Message-ID: <20211005183125.30f7df0a@coco.lan>
In-Reply-To: <20211005105110.14082-1-lecopzer.chen@mediatek.com>
References: <20211005105110.14082-1-lecopzer.chen@mediatek.com>
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Em Tue, 5 Oct 2021 18:51:10 +0800
Lecopzer Chen <lecopzer.chen@mediatek.com> escreveu:

> A case that we need VIDEO_DEV=y but DVB_CORE=m, and this doesn't
> work since DVB_CORE is default MEDIA_DIGITAL_TV_SUPPORT and then
> follows MEDIA_SUPPORT.
> 
> Change to tristate to make DVB_CORE=m possible when MEDIA_SUPPORT=y
> 
> Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
> ---
>  drivers/media/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/Kconfig b/drivers/media/Kconfig
> index b07812657cee..c3baf92b4d02 100644
> --- a/drivers/media/Kconfig
> +++ b/drivers/media/Kconfig
> @@ -88,7 +88,7 @@ config MEDIA_ANALOG_TV_SUPPORT
>  		will disable support for them.
>  
>  config MEDIA_DIGITAL_TV_SUPPORT
> -	bool
> +	tristate
>  	prompt "Digital TV" if MEDIA_SUPPORT_FILTER
>  	default y if !MEDIA_SUPPORT_FILTER
>  	help

While this change looks simple enough, not sure if this would work
for all possibilities. If I'm not mistaken, someone proposed
something similar to it, but it caused troubles with different
configurations. I don't recall any patch addressing it, but I
may be wrong.

Tf I remember correctly, the problem rises when either V4L or DVB
core is compiled as module and the other one is compiled builtin.
On such scenario, all drivers that depend on both should be
compiled as a module, or the build will fail.

Thanks,
Mauro