From mboxrd@z Thu Jan 1 00:00:00 1970 From: timo.kokkonen@offcode.fi (Timo Kokkonen) Date: Wed, 18 Feb 2015 15:51:07 +0200 Subject: [PATCHv3 0/2] watchdog: Introduce "early-timeout-sec" property In-Reply-To: <20150218141655.0445958d@bbrezillon> References: <54B53160.6060309@roeck-us.net> <20150218141655.0445958d@bbrezillon> Message-ID: <54E498CB.8010100@offcode.fi> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 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 >> > > >