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References: <5986589C150B2F49A46483AC44C7BCA490728A@ssvlexmb2.amd.com> <m13b7t7viq.fsf@ebiederm.dsl.xmission.com>
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Cc: "Lu, Yinghai" <yinghai.lu@amd.com>, Peter Stuge <stuge-linuxbios@cdy.org>,
       linux-usb-devel@lists.sourceforge.net,
       Stefan Reinauer <stepan@coresystems.de>, Greg KH <gregkh@suse.de>,
       linux-kernel@vger.kernel.org, Andi Kleen <ak@suse.de>,
       David Brownell <david-b@pacbell.net>, linuxbios@linuxbios.org
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From: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [LinuxBIOS] [linux-usb-devel] [RFC][PATCH 0/2] x86_64 Early usb debug port support.
Date: Wed, 6 Dec 2006 16:31:36 +0100
To: ebiederm@xmission.com (Eric W. Biederman)
Sender: linux-kernel-owner@vger.kernel.org
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>> What do you mean by
>> +	for (reps = 0; reps >= 0; reps++) {
>> ?
>
> If you will not reps is negative.  Roughly it is a loop
> that will timeout eventually if a usb debug cable is not present.

> So since I didn't know how many loop iterations made sense I allowed
> it to loop for 2^31 times or until reps goes negative.

This doesn't work however.  Signed overflow in C is undefined,
and GCC actually optimises accordingly (unless -fwrapv is used).


Segher

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