* Tony Lindgren <tony@xxxxxxxxxxx> [080512 18:17]: > * 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. I'll push the first two patches today, third one still needs to be checked. 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
