Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64with MCP51 laptops

[H. Peter Anvin]

Andi Kleen wrote:
> > My machine in question, for example, needs no waiting within CMOS_READs 
> > at all.   And I doubt any other chip/device needs waiting that isn't 
>
> I don't know about CMOS, but there were definitely some not too ancient
> systems (let's say not more than 10 years) who required IO delays in the
> floppy driver and the 8253/8259. But on those the jumps are already
> far too fast.

Yes, early Linux used jumps.  I believe it broke a bunch of machines 
when the P5 came out, as the jumps were too fast.  (I have to admit to 
being a bit fuzzy on this... my memory says it was the 486 and not the 
P5, but that clearly can't be the case since my first Linux box was a 
486/33.)

	-hpa
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/