Re: [PATCH v2 1/1] mux: consumer: Add dummy functions for !CONFIG_MULTIPLEXER case

From: Andy Shevchenko
Date: Sat Jul 08 2017 - 17:23:07 EST


On Sat, Jul 8, 2017 at 9:12 PM,
<sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> wrote:
> From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
>
> Add dummy functions to avoid compile time issues when CONFIG_MULTIPLEXER
> is not enabled.
>

I don't think the error return code is okay to all of them. The return
value should be choosen carefully (for some functions it's okay IMO to
return 0).

> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
> ---
> include/linux/mux/consumer.h | 38 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 38 insertions(+)
>
> Changes since v1:
> * Changed #ifdef to #if IS_ENABLED.
>
> diff --git a/include/linux/mux/consumer.h b/include/linux/mux/consumer.h
> index 5577e1b..df78988 100644
> --- a/include/linux/mux/consumer.h
> +++ b/include/linux/mux/consumer.h
> @@ -16,6 +16,7 @@
> struct device;
> struct mux_control;
>
> +#if IS_ENABLED(CONFIG_MULTIPLEXER)
> unsigned int mux_control_states(struct mux_control *mux);
> int __must_check mux_control_select(struct mux_control *mux,
> unsigned int state);
> @@ -29,4 +30,41 @@ void mux_control_put(struct mux_control *mux);
> struct mux_control *devm_mux_control_get(struct device *dev,
> const char *mux_name);
>
> +#else
> +unsigned int mux_control_states(struct mux_control *mux)
> +{
> + return -ENODEV;

Peter, is here we are obliged to return error code in such case?

> +}
> +
> +int __must_check mux_control_select(struct mux_control *mux,
> + unsigned int state)
> +{
> + return -ENODEV;

return 0; ?

> +}
> +
> +int __must_check mux_control_try_select(struct mux_control *mux,
> + unsigned int state)
> +{
> + return -ENODEV;
> +}

return 0; ?

> +
> +int mux_control_deselect(struct mux_control *mux)
> +{
> + return -ENODEV;
> +}

return 0; ?

> +
> +struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
> +{
> + return ERR_PTR(-ENODEV);
> +}
> +
> +void mux_control_put(struct mux_control *mux) {}
> +
> +struct mux_control *devm_mux_control_get(struct device *dev,
> + const char *mux_name)
> +{
> + return ERR_PTR(-ENODEV);
> +}
> +#endif
> +
> #endif /* _LINUX_MUX_CONSUMER_H */
> --
> 2.7.4
>



--
With Best Regards,
Andy Shevchenko