Intel i8xx watchdog driver

Doug Ambrisko ambrisko at ambrisko.com
Thu Mar 25 13:18:31 PST 2004


Scott Long writes:
| Wm. Daryl Hawkins wrote:
| > I've written a driver for the Intel i8xx TCO watchdog timer for both 
| > FreeBSD-CURRENT and FreeBSD-STABLE.  
|
| This is wonderful.  I'd be happy to test it and shepherd it in.  Does it
| support the intel 750x chips also?

All ICH chips that I've touched support this with the device ID updated
as needed.  FYI there is a new watchdog device in the 6300ESB.  Not
sure if it is in prior ICH chips.  It is interesting in that during the
first expire it will generate and interrupt then it will reboot on the
next expire.  So if you have an ICH then you can use it.

A nice concept would be to have a SW watchdog based on the clock tickle
the HW watchdog.  If the SW watchdog goes off you get a panic.

Interesting caveats are having the watchdogs going off while in kgdb/ddb.

Caveat to the ICH TCO timer is that if the speaker output out of the ICH 
has a pull up resistor on it then the TCO reset is disabled and will not
reset the system.  I ran into this on a motherboard at a prior company.
You cannot via SW disable this feature :-(

I have code for the SIS 630 chipset that I can give to anyone interested.

Doug A.


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