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* [PATCH] power: reset: gpio-poweroff: Replace mdelay() with msleep() in gpio_poweroff_do_poweroff()
@ 2018-07-30 13:46 Jia-Ju Bai
  2018-08-29 22:44 ` Sebastian Reichel
  0 siblings, 1 reply; 2+ messages in thread
From: Jia-Ju Bai @ 2018-07-30 13:46 UTC (permalink / raw)
  To: sre; +Cc: linux-pm, linux-kernel, Jia-Ju Bai

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@gmail.com>
---
 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


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] power: reset: gpio-poweroff: Replace mdelay() with msleep() in gpio_poweroff_do_poweroff()
  2018-07-30 13:46 [PATCH] power: reset: gpio-poweroff: Replace mdelay() with msleep() in gpio_poweroff_do_poweroff() Jia-Ju Bai
@ 2018-08-29 22:44 ` Sebastian Reichel
  0 siblings, 0 replies; 2+ messages in thread
From: Sebastian Reichel @ 2018-08-29 22:44 UTC (permalink / raw)
  To: Jia-Ju Bai; +Cc: linux-pm, linux-kernel

[-- Attachment #1: Type: text/plain, Size: 1379 bytes --]

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@gmail.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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^ permalink raw reply	[flat|nested] 2+ messages in thread

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2018-07-30 13:46 [PATCH] power: reset: gpio-poweroff: Replace mdelay() with msleep() in gpio_poweroff_do_poweroff() Jia-Ju Bai
2018-08-29 22:44 ` Sebastian Reichel

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