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

[David P. Reed]

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).

--
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/