Intel and using pins for multiple purposes

What do you need the watchdog for?

Restart the system if it hangs.

Sylvia.

I can only imagine that Intel provided a method for disabling the hardware watchdog in order to avoid an infinite boot loop in the event that the timer was set to too short a duration.

I haven't looked into the architecture, but the speaker output would likely be the least critical pin (system function wise), and would tie in well with the "system diagnostics" side of things - the motherboard manufacturer definitely seems to have botched it.

If you have a decent (i.e., very high impedance) multimeter, check the voltage on that pin at boot time. A decent DSO would be even better, but I suspect it's a simple resistive pull up to +Vcc rather than a pulse in response to something else.

If it is indeed pulling it up, simply cut the speaker circuit off - I'd suspect in your scenario watchdog time functionality would be more beneficial than the provision of a power-on beep. If you still want provision for power-on diagnostics, put a switch in there, to switch the speaker circuit back in if the system fails.

Yeah but why do you need it running unattended? If it hangs you must have a software/hardware problem. You shouldn't be using a Windoze PC for anything critical anyway.

It could also be something as simple as a flipped bit pursuant to a voltage/magnetic surge. There's a reason why 100% of dedicated servers actually have a functional watchdog implementation.

I didn't see anywhere in her post that she'd written she was using Windows.

Just for the record though, I have a server sitting here which has been running Windows (2K Server) continuously since late 2002 and hasn't once crashed due to software failure (I'll admit that it's had two PSUs and one HDD replaced in that time - but neither of these have anything to do with choice of operating system). I also have a Debian machine which falls over of its own accord at least once a week due to memory leaks in a driver.

Who said it was Windows?

I say I want to use the watchdog timer. I can't for the life of me see how you can conclude that I shouldn't want to.

Sylvia.

Though the only thing that could stuff things up that badly would be the BIOS, and if a BIOS developer gets things that wrong on a system with a BIOS rom that's soldered into place, and thereby not reflashable, they strongly deserve to have to buy a new motherboard.

After posting, I did reflect on it some more, and it certainly seems that the most obvious speaker driver implementation (and we're not talking Hi-Fi here), is not likely to function as a pull-up. I've entered a support ticket with the board manufacturer - but what are the odds that they'll just tell me to reflash to the most recent BIOS? I already did anyway, before looking at the hardware details. It didn't help, of course.

Unfortunately, I can't even reach the pin - it's a surface mounted device soldered to the board with an array of pins. I've tried backtracking from the loudspeaker driver (using a magnifying glass), but I quickly get lost, and I suspect this is a multi-layer board. Buying an X-ray machine to diagnose this seems a bit over-the-top.

If necessary, I'll just buy a third-party watchdog card.

Sylvia.

I assumed so, around 90% of PCs use it.

You normally only use a watchdog to reboot when a problem occurs. If you are having PC problems this ng might be able to help you fix them directly. So, why do you need a watchdog in the first place?

So you assumed that I was doing something critical, but that I was using Windows for it, despite, in your view, the inappropriateness of that. Seems a bit arrogant to me.

I can't fix a problem until it exists, and if one arises, then without the watchdog timer, the system will hang until such time as I notice, which I don't want.

Pretty much the standard use of watchdog timer, indeed.

Sylvia.

Not really, and no offence intended. I simply meant *if* it was critical, you shouldn't depend on Windows. Since you haven't given a reason why you want to go to the trouble of using a watchdog, I still don't know if your application is critical or not. If you are using Windows, just say so.

A watchdog reset won't fix hardware software problems. And if you aren't around to notice a crash, you won't be around to see the watchdog stuck in an endless reboot sequence either, if the fault is still present. Unless you write recovery code your PC will not resume where it left off either.

You still haven't explained what you are doing with the PC that justifies a watchdog. You may be better off with a more stable O/S instead.

It already resumes its critical task on a reboot.

Remind me why it needs to be justified.

Sylvia.

I submitted a support ticket to the board manufacturer, whose initial response was that they don't support Linux, and that I should install a Windows operating system and try it there.

I said I'be be willing to try, but that as far I can see there's no official driver for the hardware.

Their response is now that I contact Microsort for further information.

Perhaps they mean that if I get enough information from Microsoft to write a driver for the hardare, do so, and then it doesn't work, they'll take the matter seriously.

The real situation seems to be that they don't support any chipset feature that Windows doesn't use, and it's pot-luck whether it'll work.

The board, BTW, is a GA-H61M-S2PV (rev 2.0). I've also tried a revision

Sylvia.