Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <7eb4c0b9-a00e-8de5-65dd-7a44c0ec2c3a@baylibre.com>
Date:   Fri, 7 Apr 2023 16:40:14 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.9.0
Subject: Re: [PATCH] soc: mediatek: Kconfig: Add MTK_CMDQ dependency to
 MTK_MMSYS
To:     AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>, matthias.bgg@gmail.com
Cc:     linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, kernel@collabora.com
References: <20230403093304.276418-1-angelogioacchino.delregno@collabora.com>
Content-Language: en-US
From:   Alexandre Mergnat <amergnat@baylibre.com>
In-Reply-To: <20230403093304.276418-1-angelogioacchino.delregno@collabora.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 03/04/2023 11:33, AngeloGioacchino Del Regno wrote:
> The mtk-mmsys and mutex drivers do have a dependency on MTK_CMDQ,
> even though both can work with *or* without it: since CMDQ support
> can be enabled either as module or as built-in, it is necessary to
> add a depends rule in Kconfig, so that we disallow building both
> mtk-mmsys and mtk-mutex as built-in if mtk-cmdq-helper is built as
> a module, otherwise obvious linker issues appear.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
> 
> This has no Fixes tag because the commit that can produce the issue that gets
> prevented in this commit is already in the maintainer's tree.
> 
>   drivers/soc/mediatek/Kconfig | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
> index d6b83a5508ca..a88cf04fc803 100644
> --- a/drivers/soc/mediatek/Kconfig
> +++ b/drivers/soc/mediatek/Kconfig
> @@ -76,6 +76,7 @@ config MTK_MMSYS
>   	tristate "MediaTek MMSYS Support"
>   	default ARCH_MEDIATEK
>   	depends on HAS_IOMEM
> +	depends on MTK_CMDQ || MTK_CMDQ=n
>   	help
>   	  Say yes here to add support for the MediaTek Multimedia
>   	  Subsystem (MMSYS).

Hi Angelo

I guess it should also be done for DRM_MEDIATEK, if I refer to the lsmod 
result:

Module                  Size  Used by
mtk_cmdq_helper        20480  1 mediatek_drm
mtk_cmdq_mailbox       20480  1 mtk_cmdq_helper

Or is it maybe enough to protect the call of the dependent driver with 
IS_REACHABLE or IS_ENABLED helpers ?

What do you think ?

Regards,
Alexandre