Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64 with MCP51 laptops

H. Peter Anvin
2007-12-11T17:03:03Z

Rene Herman wrote:
> On 11-12-07 02:25, H. Peter Anvin wrote:
>
>> David Newall wrote:
>>> Where did the 8us delay come from? The documentation and source is
>>> careful not to say how long the delay is. Would changing it to, say
>>> 1us, be technically wrong? Is code that requires 8us correct?
>>
>> I think a single ISA bus transaction is 1 µs, so two of them back to
>> back should be 2 µs, not 8 µs...
>
> Sigh. And now where do these _two_ transactions come from? (and yes, see
> Alan's folowups, a transaction on a spec bus is 1 us).
>

Stale memory, sorry.

-hpa