* Igor Stoppa <igor.stoppa@xxxxxxxxx> [080512 17:56]: > Hi Tony, > On Mon, 2008-05-12 at 17:35 -0700, ext Tony Lindgren wrote: > > Make retu watchdog behave like a standard Linux watchdog. > > > > Let the kernel do the kicking until the watchdog device is opened. > > This is not always the desidered behavior: the powerdown wd is used to > ensure that the whole sw stack is healty: doing the kicking in > kernelspace for free introduces the case where userspace can get stuck > and the device does not powerdown. That's why there's CONFIG_WATCHDOG_NOWAYOUT where the ping timer is not enabled at all, and the watchdog is just set to max until userspace watchdog software kicking starts. > Also the unconditional loading of the maximum value during probe is not > aligned with the original reset logic, which was to have the powerdown > wd to allow for 2 boot attempts: > > -cold boot -> load max value in retu wd (63s) > -> load 30s in omap wd > -try to kick both wds Well you can set those values via /dev/watchdog too, right? And then use CONFIG_WATCHDOG_NOWAYOUT. And ff CONFIG_WATCHDOG_NOWAYOUT is not set, the kernel ping timer only happens when /dev/watchdog is not open. > if fail, then omap reboots, but retu keeps counting down > > -warm boot -> let the retu wd untouched > -> load 30s in omap wd > -try to kick both wds > > if fail, retu powers down > > That was the original idea in 770 times and i still like it. > > To conclude, i'd see inkernel kicking more as a debugging feature while > one is hacking at the kernel than a desirable quality of a stable > kernel. Considering that the /dev/watchdog interface is the standard, I see this patch as the only way we can get this code ever merged upstream. And it's easy to patch back the non-standard if you want to. Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
