[PATCHv3 0/2] watchdog: Introduce "early-timeout-sec" property

Boris Brezillon boris.brezillon at free-electrons.com
Wed Feb 18 05:16:55 PST 2015


Hi Timo,

Could you send new versions of this in their own thread (not in reply
to previous versions), and increment the version in patch 1 and 2 ?

Could you also summarize what has changed between each versions in this
cover letter ?

Best Regards,

Boris

On Wed, 18 Feb 2015 14:57:20 +0200
Timo Kokkonen <timo.kokkonen at offcode.fi> wrote:

> Currently we have no means to adjust the watchdog behavior on early
> start up before user space has opened the device. The generic behavior
> among the watchdog drivers is to not start the watchdog at all (or
> disable it, if possible, or in case at91sam9_wdt, start a kernel timer
> that keeps on pinging the watchdog on behalf of user space until a
> watchdog daemon opens it). This unfortunately opens a time window
> between starting the driver and starting the user space watchdog
> daemon where a crash of the kernel or user space might prevent the
> watchdog from ever resetting the device at all. This is obviously bad
> on production systems.
> 
> Introduce a new device tree property that, when set, changes the
> watchdog driver behavior in such way that there no longer is any
> window where crash is not caught by the watchdog.
> 
> This is the third version of this patch. Previous versions of the
> patch were using an atmel specific property name. This patch uses a
> generic name instead as the functionality itself has nothing atmel
> related. I am also introducing watchdog.txt for describing the generic
> watchdog device tree bindings as there was no such file before.
> 
> Timo Kokkonen (2):
>   devicetree: Document generic watchdog properties
>   at91sam9_wdt: Allow watchdog to reset device at early boot
> 
>  .../devicetree/bindings/watchdog/watchdog.txt         | 19 +++++++++++++++++++
>  drivers/watchdog/at91sam9_wdt.c                       |  9 ++++++++-
>  2 files changed, 27 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/watchdog/watchdog.txt
> 



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



More information about the linux-arm-kernel mailing list