Subject: Re: [PATCH 1/5] remove TxStartThresh and RxEarlyThresh
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jesse Huang <jesse@icplus.com.tw>, linux-kernel@vger.kernel.org,
       netdev@vger.kernel.org, akpm@osdl.org, jgarzik@pobox.com
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Date: Sun, 15 Oct 2006 23:59:20 +0100
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Ar Llu, 2006-10-16 am 07:26 +1000, ysgrifennodd Benjamin Herrenschmidt:
> On Sat, 2006-10-14 at 15:55 -0400, Jesse Huang wrote:
> > From: Jesse Huang <jesse@icplus.com.tw>
> > 
> > Change Logs:
> > For patent issue need to remove TxStartThresh and RxEarlyThresh. This patent 
> > is cut-through patent. If use this function, Tx will start to transmit after 
> > few data be move in to Tx FIFO. We are not allow to use those function in 
> > DFE530/DFE550/DFE580/DL10050/IP100/IP100A. It will decrease a little 
> > performance.
> 
> Somebody patented FIFO thresholds ? Gack ?

3COM hold several patents on certain kinds of early interrupt/early
start for network FIFOs. At least historically they also had a GPL Linux
driver that didn't use that feature on their own cards which I'm told
was fear of patent "leakage"

Alan
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