On Mon, Nov 28, 2016 at 02:24:30PM +0100, Allan W. Nielsen wrote: > From: Raju Lakkaraju <raju.lakkar...@microsemi.com> > > 3 types of PHY loopback are supported. > i.e. Near-End Loopback, Far-End Loopback and External Loopback.
Hi Allan Is this integrated with ethtool --test? You only want the PHY to go into loopback mode when running ethtool --test external_lb or maybe ethtool --test offline. What i think should happen is that this tunable sets the mode the PHY will go into when loopback is enabled. It does not however enable loopback. It is running ethtool --test which actually enables the loopback, probably by setting BMCR_LOOPBACK. Once the test is finished, the bit is cleared and the PHY goes back into normal operation. Andrew