Hi Kumar, > I was hoping to get some ideas on how to handle the watchdog timers > we have on some embedded PPC (booke_wdt.c) cores when we are in a SMP > system. > > The problem is since the watchdog is part of the processor core > depending on which processor a given system call is executed at we > might get different behavior. It seems like we would want to mirror > the actions to both cores (via smp_call_function). > > Looking at the file ops we currently support in booke_wdt.c it seems > like we could mirror the actions for booke_wdt_write()/booke_wdt_ping > () to both cores and ensure when we set something like > WDIOC_SETTIMEOUT we set the registers in both processors. > > I was wondering if anyone had any other ideas or if this model seems > to work.
I see 2 ways to go: 1) short term: make sure that your actions are duplicated to both cores (like you said). At least then you are protected if your complete system crashes. 2) I'm working on the uniform/generic watchdog device driver. Phase 1 is the "new" api and the /dev/watchdog handling. Phase 2 is a sysfs interface. Phase 3 is to allow multiple devices (and there I'm still thinking about how the /dev/watchdog interface should work). But the general idea is to allow at least the control of each watchdog device by the sysfs interface. Greetings, Wim. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
