On Fri, May 31, 2013 at 03:05:50PM +0530, anish singh wrote: > Hi Guenter, > > On Fri, May 31, 2013 at 3:32 AM, Guenter Roeck <li...@roeck-us.net> 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?
I don't mind, but you might want to wait for Wim's feedback. Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
