From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@roeck-us.net (Guenter Roeck) Date: Fri, 20 Feb 2015 08:09:53 -0800 Subject: [PATCH 2/2] at91sam9_wdt: Allow watchdog to reset device at early boot In-Reply-To: <00B1658F-2F3A-4B90-ADCA-275770832180@jcrosoft.com> References: <54B53160.6060309@roeck-us.net> <6c0a3a5bcd93d18437eeed04712b4aeff201a16f.1424262664.git.timo.kokkonen@offcode.fi> <00B1658F-2F3A-4B90-ADCA-275770832180@jcrosoft.com> Message-ID: <20150220160953.GA22752@roeck-us.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Feb 20, 2015 at 03:48:22PM +0800, Jean-Christophe PLAGNIOL-VILLARD wrote: > > > On Feb 18, 2015, at 8:57 PM, Timo Kokkonen 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 > > --- > > 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 > Sure, and it has been in the back of my mind for a couple of years. Care to submit a set of patches to implement it ? Guenter