[PATCH 2/2] at91sam9_wdt: Allow watchdog to reset device at early boot

[Boris Brezillon]

Hi Jean-Christophe,

On Fri, 20 Feb 2015 15:48:22 +0800
Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com> wrote:

> 
> > On Feb 18, 2015, at 8:57 PM, Timo Kokkonen <timo.kokkonen at offcode.fi> wrote:
> > 
> > By default the driver will start a kernel timer which keeps on kicking
> > the watchdog HW until user space has opened the watchdog
> > device. Usually this is desirable as the watchdog HW is running by
> > default and the user space may not have any watchdog daemon running at
> > all.
> > 
> > However, on production systems it may be mandatory that also early
> > crashes and lockups will lead to a watchdog reset, even if they happen
> > before the user space has opened the watchdog device.
> > 
> > To resolve the issue, add a new device tree property
> > "early-timeout-sec" which will let the kernel timer to ping the
> > watchdog HW only as long as the specified timeout permits. The default
> > is still to use kernel timer, but more strict behavior can be enabled
> > via the device tree property.
> > 
> > Signed-off-by: Timo Kokkonen <timo.kokkonen at offcode.fi>
> > ---
> > Documentation/devicetree/bindings/watchdog/watchdog.txt | 7 +++++++
> > drivers/watchdog/at91sam9_wdt.c                         | 9 ++++++++-
> 
> This should not be handled by the driver but the kernel in a generic way

Could you detail a bit more what you have in mind ?

Best Regards,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com