Date: Sat, 8 Dec 2007 21:04:27 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: "David P. Reed" <dpreed@reed.com>
Cc: Andi Kleen <andi@firstfloor.org>, 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: <20071208210427.535aa9a0@the-village.bc.nu>
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> The point here is that Linux is NOT using a defined-to-be "unused" 
> port.  It IS using the "diagnostic" port, and talking to a diagnostic 
> device that *is* used, and may be present.

Just like millions of other pieces of software from the same era. 

> 2) Start a background task with the maintainers of drivers to clean up 
> their code regarding these short delays for slow devices (note that it's 
> never because the *bus* is slow, but because the *device* is slow.)  
> Perhaps this could be helped by "deprecating" the _p calls and 
> suggesting an alternative that requires the coder to be precise about 
> what the delay is for, and how long it is supposed to be, perhaps on a 
> per-machine basis.

Send patches. For a lot of the devices we know what the requirements are
as its locked to ISA cycle times.

Alan
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