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. 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/
