Date: Fri, 7 Dec 2007 00:15:33 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: "David P. Reed" <dpreed@reed.com>
Cc: linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
       Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64
 with MCP51 laptops
Message-ID: <20071207001533.7737ecf5@the-village.bc.nu>
In-Reply-To: <475879CD.9080006@reed.com>
References: <475879CD.9080006@reed.com>
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> Changing the delay instruction sequence from the outb to short jumps 
> might be the safe thing.  But Linus, et al. may have experience with 
> that on other architectures like older Pentiums etc.

Post boot we can use udelay() for this. Earlier I guess we could use
udelay and make sure it starts "safe" before we know the timing.

Alan
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