[PATCH] watchdog: aspeed: replace mdelay with msleep

[PATCH] watchdog: aspeed: replace mdelay with msleep

[Phil Eichinger]

Since it is not called in an atomic context the mdelay function
can be replaced with msleep to avoid busy wait.

Signed-off-by: Phil Eichinger <phil@zankapfel.net>
---
 drivers/watchdog/aspeed_wdt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
index b4773a6aaf8c..98ef341408f7 100644
--- a/drivers/watchdog/aspeed_wdt.c
+++ b/drivers/watchdog/aspeed_wdt.c
@@ -208,7 +208,7 @@ static int aspeed_wdt_restart(struct watchdog_device *wdd,
 	wdt->ctrl &= ~WDT_CTRL_BOOT_SECONDARY;
 	aspeed_wdt_enable(wdt, 128 * WDT_RATE_1MHZ / 1000);
 
-	mdelay(1000);
+	msleep(1000);
 
 	return 0;
 }
-- 
2.39.5

Re: [PATCH] watchdog: aspeed: replace mdelay with msleep

[Guenter Roeck]

On 12/12/24 03:30, Phil Eichinger wrote:
> Since it is not called in an atomic context the mdelay function
> can be replaced with msleep to avoid busy wait.
> 
> Signed-off-by: Phil Eichinger <phil@zankapfel.net>
> ---
>   drivers/watchdog/aspeed_wdt.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
> index b4773a6aaf8c..98ef341408f7 100644
> --- a/drivers/watchdog/aspeed_wdt.c
> +++ b/drivers/watchdog/aspeed_wdt.c
> @@ -208,7 +208,7 @@ static int aspeed_wdt_restart(struct watchdog_device *wdd,
>   	wdt->ctrl &= ~WDT_CTRL_BOOT_SECONDARY;
>   	aspeed_wdt_enable(wdt, 128 * WDT_RATE_1MHZ / 1000);
>   
> -	mdelay(1000);
> +	msleep(1000);
>   
>   	return 0;
>   }
This is a _restart_ handler. The only purpose of the delay is to wait
for the reset to trigger. It is not supposed to sleep.

NACK.

Guenter

RE: [PATCH] watchdog: aspeed: replace mdelay with msleep

[David Laight]

From: Guenter Roeck
> Sent: 12 December 2024 13:56
> To: Phil Eichinger <phil@zankapfel.net>; wim@linux-watchdog.org; joel@jms.id.au;
> andrew@codeconstruct.com.au; linux-watchdog@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> linux-aspeed@lists.ozlabs.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH] watchdog: aspeed: replace mdelay with msleep
> 
> On 12/12/24 03:30, Phil Eichinger wrote:
> > Since it is not called in an atomic context the mdelay function
> > can be replaced with msleep to avoid busy wait.
> >
> > Signed-off-by: Phil Eichinger <phil@zankapfel.net>
> > ---
> >   drivers/watchdog/aspeed_wdt.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
> > index b4773a6aaf8c..98ef341408f7 100644
> > --- a/drivers/watchdog/aspeed_wdt.c
> > +++ b/drivers/watchdog/aspeed_wdt.c
> > @@ -208,7 +208,7 @@ static int aspeed_wdt_restart(struct watchdog_device *wdd,
> >   	wdt->ctrl &= ~WDT_CTRL_BOOT_SECONDARY;
> >   	aspeed_wdt_enable(wdt, 128 * WDT_RATE_1MHZ / 1000);
> >
> > -	mdelay(1000);
> > +	msleep(1000);
> >
> >   	return 0;
> >   }
> This is a _restart_ handler. The only purpose of the delay is to wait
> for the reset to trigger. It is not supposed to sleep.

With the recent scheduler changes isn't the code likely to get
pre-empted?
Which (effectively) converts is to a sleep?

	David
 
> 
> NACK.
> 
> Guenter
> 
> 
> 

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: [PATCH] watchdog: aspeed: replace mdelay with msleep

[Guenter Roeck]

On 12/14/24 13:21, David Laight wrote:
> From: Guenter Roeck
>> Sent: 12 December 2024 13:56
>> To: Phil Eichinger <phil@zankapfel.net>; wim@linux-watchdog.org; joel@jms.id.au;
>> andrew@codeconstruct.com.au; linux-watchdog@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
>> linux-aspeed@lists.ozlabs.org; linux-kernel@vger.kernel.org
>> Subject: Re: [PATCH] watchdog: aspeed: replace mdelay with msleep
>>
>> On 12/12/24 03:30, Phil Eichinger wrote:
>>> Since it is not called in an atomic context the mdelay function
>>> can be replaced with msleep to avoid busy wait.
>>>
>>> Signed-off-by: Phil Eichinger <phil@zankapfel.net>
>>> ---
>>>    drivers/watchdog/aspeed_wdt.c | 2 +-
>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
>>> index b4773a6aaf8c..98ef341408f7 100644
>>> --- a/drivers/watchdog/aspeed_wdt.c
>>> +++ b/drivers/watchdog/aspeed_wdt.c
>>> @@ -208,7 +208,7 @@ static int aspeed_wdt_restart(struct watchdog_device *wdd,
>>>    	wdt->ctrl &= ~WDT_CTRL_BOOT_SECONDARY;
>>>    	aspeed_wdt_enable(wdt, 128 * WDT_RATE_1MHZ / 1000);
>>>
>>> -	mdelay(1000);
>>> +	msleep(1000);
>>>
>>>    	return 0;
>>>    }
>> This is a _restart_ handler. The only purpose of the delay is to wait
>> for the reset to trigger. It is not supposed to sleep.
> 
> With the recent scheduler changes isn't the code likely to get
> pre-empted?
> Which (effectively) converts is to a sleep?
> 

This code is called from do_kernel_restart(), which in turn is called from
machine_restart(). I'd think that the kernel has a severe problem if it
decides to preempt that function.

Guenter