linux-kernel - Re: [PATCH] power: reset: gpio-poweroff: Replace mdelay() with msleep() in gpio_poweroff_do

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Date:   Thu, 30 Aug 2018 00:44:09 +0200
From:   Sebastian Reichel <sebastian.reichel@...labora.com>
To:     Jia-Ju Bai <baijiaju1990@...il.com>
Cc:     linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] power: reset: gpio-poweroff: Replace mdelay() with
 msleep() in gpio_poweroff_do_poweroff()

Hi,

On Mon, Jul 30, 2018 at 09:46:14PM +0800, Jia-Ju Bai wrote:
> gpio_poweroff_do_poweroff() is never called in atomic context.
> It calls mdelay() to busily wait, which is not necessary.
> mdelay() can be replaced with msleep().
> 
> This is found by a static analysis tool named DCNS written by myself.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@...il.com>
> ---

Please self-review the results from your tool before sending.
This is a shutdown driver.

-- Sebastian

>  drivers/power/reset/gpio-poweroff.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/power/reset/gpio-poweroff.c b/drivers/power/reset/gpio-poweroff.c
> index 6273ad3b411d..bbe55cfa87d0 100644
> --- a/drivers/power/reset/gpio-poweroff.c
> +++ b/drivers/power/reset/gpio-poweroff.c
> @@ -33,16 +33,16 @@ static void gpio_poweroff_do_poweroff(void)
>  
>  	/* drive it active, also inactive->active edge */
>  	gpiod_direction_output(reset_gpio, 1);
> -	mdelay(100);
> +	msleep(100);
>  	/* drive inactive, also active->inactive edge */
>  	gpiod_set_value(reset_gpio, 0);
> -	mdelay(100);
> +	msleep(100);
>  
>  	/* drive it active, also inactive->active edge */
>  	gpiod_set_value(reset_gpio, 1);
>  
>  	/* give it some time */
> -	mdelay(timeout);
> +	msleep(timeout);
>  
>  	WARN_ON(1);
>  }
> -- 
> 2.17.0
> 

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