Messages in this thread | | | Date | Mon, 22 Sep 2003 17:26:02 +0100 | From | Jamie Lokier <> | Subject | Re: Can we kill f inb_p, outb_p and other random I/O on port 0x80, in 2.6? |
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Alan Cox wrote: > (one part of the problem of course is you need inb_p/outb_p to drive > the timer chip on some x86 boards in order to calibrate the udelay > timer)
What sort of timer chip problems do you see? Is it something that can be auto-detected, so that timer chip accesses can be made faster on boards where that is fine?
I'm sure I've seen timer chip code in DOS programs that didn't have the extra delay I/Os. Surely it cannot be a very widespread problem.
> > When debugging this I modified arch/i386/io.h to read: > > #define __SLOW_DOWN_IO__ "" > > Which totally removed the delay and the system ran fine. > > Not all systems do - we had breakages from both the keyboard controller > and the timer chips even on some modern boards when this got messed up.
I've also seen much DOS code that didn't have extra delays for keyboard I/Os. What sort of breakage did you observe with the keyboard?
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