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Message-ID: <82e0812e-c6db-9f69-b968-794a0f6b915a@collabora.com>
Date:   Tue, 14 Jun 2022 10:27:04 +0200
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Subject: Re: [PATCH v2 2/7] usb: typec: mux: Add CONFIG guards for functions
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To:     Prashant Malani <pmalani@chromium.org>,
        linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Cc:     heikki.krogerus@linux.intel.com,
        Andrzej Hajda <andrzej.hajda@intel.com>,
        Neil Armstrong <narmstrong@baylibre.com>,
        David Airlie <airlied@linux.ie>,
        "open list:DRM DRIVERS" <dri-devel@lists.freedesktop.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Sam Ravnborg <sam@ravnborg.org>,
        kernel test robot <lkp@intel.com>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Tzung-Bi Shih <tzungbi@google.com>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        =?UTF-8?B?TsOtY29sYXMgRi4gUi4gQS4gUHJhZG8=?= 
        <nfraprado@collabora.com>, Jonas Karlman <jonas@kwiboo.se>,
        swboyd@chromium.org, Pin-Yen Lin <treapking@chromium.org>,
        Rob Herring <robh+dt@kernel.org>,
        Maxime Ripard <maxime@cerno.tech>,
        Hsin-Yi Wang <hsinyi@chromium.org>,
        Xin Ji <xji@analogixsemi.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Robert Foss <robert.foss@linaro.org>,
        =?UTF-8?B?Sm9zw6kgRXhww7NzaXRv?= <jose.exposito89@gmail.com>
References: <20220609181106.3695103-1-pmalani@chromium.org>
 <20220609181106.3695103-3-pmalani@chromium.org>
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <20220609181106.3695103-3-pmalani@chromium.org>
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Precedence: bulk

Il 09/06/22 20:09, Prashant Malani ha scritto:
> There are some drivers that can use the Type C mux API, but don't have
> to. Introduce CONFIG guards for the mux functions so that drivers can
> include the header file and not run into compilation errors on systems
> which don't have CONFIG_TYPEC enabled. When CONFIG_TYPEC is not enabled,
> the Type C mux functions will be stub versions of the original calls.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Prashant Malani <pmalani@chromium.org>
> ---
> 
> Changes since v1:
> - Added static inline to stub functions.
> - Updated function signature of stub functions from "struct typec_mux"
>    to "struct typec_mux_dev" in accordance with updates from commit
>    713fd49b430c ("usb: typec: mux: Introduce indirection")
> 
>   include/linux/usb/typec_mux.h | 38 +++++++++++++++++++++++++++++++++++
>   1 file changed, 38 insertions(+)
> 
> diff --git a/include/linux/usb/typec_mux.h b/include/linux/usb/typec_mux.h
> index ee57781dcf28..9eda6146fd26 100644
> --- a/include/linux/usb/typec_mux.h
> +++ b/include/linux/usb/typec_mux.h
> @@ -58,6 +58,8 @@ struct typec_mux_desc {
>   	void *drvdata;
>   };
>   
> +#if IS_ENABLED(CONFIG_TYPEC) || IS_MODULE(CONFIG_TYPEC)

IS_ENABLED(x) evaluates to 1 when (x == 'y' || x == 'm')
IS_MODULE(x) evaluates to 1 when              (x == 'm')

....this means that a IS_ENABLED(CONFIG_TYPEC) check is enough, and
the latter is redundant.

Regards,
Angelo