Re: ioport conflict with "dma page reg" (0x80)

Rogier Wolff (R.E.Wolff@BitWizard.nl)
Tue, 16 Mar 1999 09:10:49 +0100 (MET)

Richard B. Johnson wrote:
> On Mon, 15 Mar 1999, Wall, Tim wrote:
>
> > I have a single-board computer with a hardware watchdog which uses I/O
> > addresses 0x80, 0x443, and 0x444.
> >
> > The problem is that something else in the system is writing to 0x80,
> > which resets/disables the watchdog.
> >
>
> 0x80 is the manufacturing test port. If you have a watchdog that
> cares about that, it's broken. The kernel didn't reserve it, the
> AT-Class hardware did. In fact during POST, you can read numbers
> written to that port to see how far a, possibly defective, board
> has gotten upon power up.

But, using port 0x80 to keep the watchdog from activating is a good
way of making sure that the system comes through the POST before the
watchdog kicks in....

Read Alans reply for the hint on how to get along.

Roger.

-- 
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 **
*-- BitWizard writes Linux device drivers for any device you may have! --*
*   Never blow in a cat's ear because if you do, usually after three or  *
*   four times, they will bite your lips!  And they don't let go for at  *
*   least a minute. -- Lisa Coburn, age 9


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