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* watchdog timeout in sub-seconds?
@ 2015-04-13 13:33 Alexander Stein
  2015-04-13 13:53 ` Guenter Roeck
  0 siblings, 1 reply; 3+ messages in thread
From: Alexander Stein @ 2015-04-13 13:33 UTC (permalink / raw)
  To: linux-watchdog

Hi,

is there a specific reason that the timeout in the linux watchdog drivers is 
only provided in seconds resolution? What about timeouts in ms area/precision?

Best regards,
Alexander
-- 
Dipl.-Inf. Alexander Stein

SYS TEC electronic GmbH
Am Windrad 2
08468 Heinsdorfergrund
Tel.: 03765 38600-1156
Fax: 03765 38600-4100
Email: alexander.stein@systec-electronic.com
Website: www.systec-electronic.com
 
Managing Director: Dipl.-Phys. Siegmar Schmidt
Commercial registry: Amtsgericht Chemnitz, HRB 28082


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: watchdog timeout in sub-seconds?
  2015-04-13 13:33 watchdog timeout in sub-seconds? Alexander Stein
@ 2015-04-13 13:53 ` Guenter Roeck
  2015-04-14  8:15   ` Alexander Stein
  0 siblings, 1 reply; 3+ messages in thread
From: Guenter Roeck @ 2015-04-13 13:53 UTC (permalink / raw)
  To: Alexander Stein, linux-watchdog

On 04/13/2015 06:33 AM, Alexander Stein wrote:
> Hi,
>
> is there a specific reason that the timeout in the linux watchdog drivers is
> only provided in seconds resolution? What about timeouts in ms area/precision?
>

The question would probably be why not. On a loaded system, sub-second
watchdog timeouts are quite unreasonable.

In other words, you would have to provide a very good argument for
sub-second timeouts if you see the need for it. That some hardware
may require it is not really an argument here - this is all about
user space - kernel interface, not about limitations of specific
hardware.

Guenter


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: watchdog timeout in sub-seconds?
  2015-04-13 13:53 ` Guenter Roeck
@ 2015-04-14  8:15   ` Alexander Stein
  0 siblings, 0 replies; 3+ messages in thread
From: Alexander Stein @ 2015-04-14  8:15 UTC (permalink / raw)
  To: Guenter Roeck; +Cc: linux-watchdog

On Monday 13 April 2015 06:53:02, Guenter Roeck wrote:
> On 04/13/2015 06:33 AM, Alexander Stein wrote:
> > Hi,
> >
> > is there a specific reason that the timeout in the linux watchdog drivers is
> > only provided in seconds resolution? What about timeouts in ms area/precision?
> >
> 
> The question would probably be why not. On a loaded system, sub-second
> watchdog timeouts are quite unreasonable.
> 
> In other words, you would have to provide a very good argument for
> sub-second timeouts if you see the need for it. That some hardware
> may require it is not really an argument here - this is all about
> user space - kernel interface, not about limitations of specific
> hardware.

Well, after discussing this a bit why the hardware watchdog has ms resolution support it turns out this is mainly for safety related devices which seem to require such short timeouts. It doesn't seem to be required on this linux based board though. So this issue has been cleared itself.

Best regards,
Alexander
-- 
Dipl.-Inf. Alexander Stein

SYS TEC electronic GmbH
Am Windrad 2
08468 Heinsdorfergrund
Tel.: 03765 38600-1156
Fax: 03765 38600-4100
Email: alexander.stein@systec-electronic.com
Website: www.systec-electronic.com
 
Managing Director: Dipl.-Phys. Siegmar Schmidt
Commercial registry: Amtsgericht Chemnitz, HRB 28082

^ permalink raw reply	[flat|nested] 3+ messages in thread

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2015-04-13 13:33 watchdog timeout in sub-seconds? Alexander Stein
2015-04-13 13:53 ` Guenter Roeck
2015-04-14  8:15   ` Alexander Stein

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