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

[Pavel Machek <pavel@ucw.cz>]

Hi!

>> Anyways it looks like the discussion here is going in a
>> a loop. I had hoped David would post his test results with
>> another port so that we know for sure that the bus aborts (and not port 
>> 80) is the problem on his box. But it looks like
>> he doesn't want to do this. Still removing the bus aborts
>> is probably the correct way to go forward.
>
> Yes, I do also still want to know that. David (Reed)?
>
>> Only needs a patch now. If nobody beats me to it i'll
>> add one later to my tree.
>
> Pavel Machek already posted one. His udelay(8) wants to be less -- 1 or "to 
> be safe" perhaps 2.
>
> http://lkml.org/lkml/2007/12/9/131

2 at least; that's how long outb(0x80) takes on one of my
machines. Actually, ISA can go down to 4MHz, so maybe we should be
using 4 usec.... but I guess I'm paranoid here.
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/