Re: net/hsr: not working : High-availability Seamless Redundancy (HSRv0)

From: Arvid Brodin <arvid.brodin@alten.se>
To: Gokul C G <gokul.g@kalkitech.in>, <netdev@vger.kernel.org>
Cc: <davem@davemloft.net>
Subject: Re: net/hsr: not working :  High-availability Seamless Redundancy (HSRv0)
Date: Wed, 18 Jun 2014 18:00:52 +0200	[thread overview]
Message-ID: <53A1B7B4.8010105@alten.se> (raw)
In-Reply-To: <539EE434.7050901@kalkitech.in>

On 2014-06-16 14:33, Gokul C G wrote:
> Hi,
> 
> PRP is protected by a number of patents. Does we need to  obtain
> license for those to make use of the patented technology and offer a
> PRP driver to end customers , if we use linux in embedded platform
> ??

I am not a patent expert, nor a lawyer, so I cannot advise you in this matter.
My understanding as a layman is that if there is a valid patent that covers the
code, then yes, you need to obtain a license to be allowed to offer a product
making use of the technology to end customers.

> I could find something like following while googling about HSR/PRP , 
> "In order to be compliant with the Linux open source licensing model,
> the Linux implementation of the PRP driver is in user space, not
> kernel space."  I couldn't understand the same !!

From a patent perspective, I don't *think* it matters if the implementation is 
in kernel space or user space; you'd need a license either way. By implementing 
the driver in user space you don't have to make the source code available under 
GPL, though. Again, I am not a lawyer, so don't take my word for it.

> whether Kernel implementation of HSR is problematic from a legal
> point of view (patent violation, see above for PRP) ??

Possibly. The HSRv0 standard cautions about patents regarding PRP (the PRP 
duplicate discard algorithm, using a Redundancy Control Trailer) and interactions
between HSR and PRP nets. HSR does not use a Redundancy Control Trailer.

The HSRv1 standard also cautions about patent claims for interconnecting HSR nets
though QuadBoxes, and additional PRP patents. 

I have no idea if these claims are valid, and I don't know if these are the only 
parts of the standard which may be patent encumbered. 

From the standard: "ISO (www.iso.org/patents) and IEC (http://patents.iec.ch) 
maintain on-line data bases of patents relevant to their standards. Users are 
encouraged to consult the data bases for the most up to date information 
concerning patents."

-- 
Arvid Brodin | Consultant (Linux)
ALTEN | Knarrarnäsgatan 7 | SE-164 40 Kista | Sweden
arvid.brodin@alten.se | www.alten.se/en/