From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Wed, 18 Feb 2015 14:16:55 +0100 Subject: [PATCHv3 0/2] watchdog: Introduce "early-timeout-sec" property In-Reply-To: References: <54B53160.6060309@roeck-us.net> Message-ID: <20150218141655.0445958d@bbrezillon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 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