Date: Thu, 30 Aug 2007 08:29:19 -0600
From: Robert Hancock <hancockr@shaw.ca>
Subject: Re: [PATCH] Override 80-wire cable detection for Toshiba S1800-814
In-reply-to: <fa.xZcOyxsTcgfWflTXq8DY8M1ncqc@ifi.uio.no>
To: Al Boldi <a1426z@gawab.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>, linux-kernel@vger.kernel.org,
       dex@dragonslave.de
Message-id: <46D6D43F.8040803@shaw.ca>
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Al Boldi wrote:
> Alan Cox wrote:
>>> Wow!  I have been running 80wire cable detection override on 40wire
>>> cables for quite some time without any problem, but I never thought it
>>> to be legal if the 40wire cable length is short enough.
>> Yes.
>>
>>> How short does it have to be, and can't we have a kernel bootparm to
>>> override the cable detection?
>> For most users the goal should be to automate behaviour. It should just
>> work.
> 
> What's the max length of a 40wire cable to sustain 80wire cable 
> characteristics?

This is normally only the case on a laptop, where the cable is 
essentially just a tiny stub between the motherboard and the drive. I 
suspect this is something that the system manufacturer has to validate 
works properly, more than any hard and fast limit.

For a normal desktop PC, it would be far better to just use an 80-wire 
cable.

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/

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