Hi Guenter, On Fri, May 31, 2013 at 3:32 AM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > On Thu, May 30, 2013 at 11:59:28PM +0200, Wim Van Sebroeck wrote: >> Hi Guenter, >> >> > On Tue, May 28, 2013 at 10:10:53AM +0200, Johannes Thumshirn wrote: >> > > On Mon, May 27, 2013 at 08:25:54PM +0200, Wim Van Sebroeck wrote: >> > > [...] >> > > > > + watchdog_set_drvdata(&a21_wdt, drv); >> > > > >> > > > I am missing the initialisation of the watchdog's timeout value here... >> > > >> > > This watchdog only knows two timeout values, 1s and 30s with the constraint >> > > that you can't go back to 30s once your in a 1s timeout without a reset of the >> > > CPLD. I could initially set it to 30s but that would be redundant. >> > > >> > I wonder - why bother with supporting one-second timeouts ? >> > >> > Is this realistic, ie can you guarantee that the watchdog will be pinged fast >> > enough to keep the system alive under all load conditions ? As far as I know >> > you can not even configure the watchdog application for less than 1 second >> > ping intervals. >> >> that's why certain drivers use a timer to keep kicking the watchdog at >> a rate of 0.5s (do a grep on HZ/2) untill userspace times out. >> (example: drivers/watchdog/pika_wdt.c or drivers/watchdog/pcwd.c). >> > Yes, I have used the same trick in a couple of my drivers. That isn't done here, > though. > > I even thought about adding this capability to the infrastructure. If you don't mind can I give it a try? > > Thanks, > Guenter > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
