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

[Timo Kokkonen]

Hi Boris,

Thanks for your comments. I will resend tomorrow!

-Timo

On 18.02.2015 15:16, Boris Brezillon wrote:
> 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
>>
>
>
>