Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override.

David P. Reed wrote:

H. Peter Anvin wrote:

Rene Herman wrote:

I do not know how universal that is, but _reading_ port 0xf0 might in fact be sensible then? And should even work on a 386/387 pair? (I have a 386/387 in fact, although I'd need to dig it up).

No.  Someone might have used 0xf0 as a readonly port for other uses.

As support: port 80 on the reporter's (my) HP dv9000z laptop clearly responds to reads differently than "unused" ports. In particular, an inb takes 1/2 the elapsed time compared to a read to "known" unused port 0xed - 792 tsc ticks for port 80 compared to about 1450 tsc ticks for port 0xed and other unused ports (tsc at 800 MHz).

Any timings for port 0xf0 (write zero), out of curiosity?

	-hpa
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