Subject: Re: [PATCH v2] ethtool : Allow ethtool to set interface in loopback mode.

From: Ben Hutchings <[email-masked]>
Date: Fri, 03 Dec 2010 16:33:34 +0000

On Fri, 2010-12-03 at 17:03 +0100, David Lamparter wrote:
> On Thu, Dec 02, 2010 at 02:35:51PM -0800, Mahesh Bandewar wrote:
> > This patch adds -L command-line option to switch loopback mode on/off
> > and -l option to display current loopback mode on a specified interface.
> [...]
> > +.A1 on off
> > +Switches loopback mode
> > +.B on
> > +or
> > +.B off
> 
> What about devices that support different kinds of loopback, like MAC
> loopback & PHY loopback? (No idea if we have kernel support for this
> either...)

That distinction is useful for diagnostic purposes, but drivers can
already cover those different loopback modes in self-test.  The
motivation for this feature is testing data path behaviour, and Mahesh
has specified that loopback should be enabled as near as possible to the
host.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.