Re: [PATCH 4/4] iio: auxadc: mediatek: change to subsys_initcall

[Jonathan Cameron]

On Thu, 16 May 2019 16:10:47 +0800
Chun-Hung Wu <chun-hung.wu@xxxxxxxxxxxx> wrote:

>   Move auxadc platform_driver_register() from module_init
> to subsys_initcall because auxadc user drivers
> are all moudle drivers, need to gurantee
> auxadc driver ready before module_init.
> 
Is it not possible to make them use deferred handling to come
back later if this isn't yet available?

subsys_initcall often ends up being a more fragile approach.

Thanks,

Jonathan

> Signed-off-by: Chun-Hung Wu <chun-hung.wu@xxxxxxxxxxxx>
> ---
>  drivers/iio/adc/mt6577_auxadc.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/adc/mt6577_auxadc.c b/drivers/iio/adc/mt6577_auxadc.c
> index 58d7cb2..cb8e3dd 100644
> --- a/drivers/iio/adc/mt6577_auxadc.c
> +++ b/drivers/iio/adc/mt6577_auxadc.c
> @@ -350,7 +350,19 @@ static int mt6577_auxadc_remove(struct platform_device *pdev)
>  	.probe	= mt6577_auxadc_probe,
>  	.remove	= mt6577_auxadc_remove,
>  };
> -module_platform_driver(mt6577_auxadc_driver);
> +
> +static int __init mt6577_auxadc_init(void)
> +{
> +	return platform_driver_register(&mt6577_auxadc_driver);
> +}
> +
> +static void __exit mt6577_auxadc_exit(void)
> +{
> +	platform_driver_unregister(&mt6577_auxadc_driver);
> +}
> +
> +subsys_initcall(mt6577_auxadc_init);
> +module_exit(mt6577_auxadc_exit);
>  
>  MODULE_AUTHOR("Zhiyong Tao <zhiyong.tao@xxxxxxxxxxxx>");
>  MODULE_DESCRIPTION("MTK AUXADC Device Driver");