Subject: Re: Configuring synchronous ethernet with ethtool?

From: Richard Cochran <[email-masked]>
Date: Sat, 4 Apr 2015 22:03:44 +0200

On Sat, Apr 04, 2015 at 02:59:10PM +0100, Ben Hutchings wrote:
> The 'manual' setting matches terminology in IEEE 802.3 (section 40.5.2).
> There's no mention of 'preferred' there but perhaps this switch will
> claim to be a single-port if you say it should prefer slave mode.

Thanks for the reference.  The switch I was talking about has control
register 9 implemented exactly as described in 802.3, but the TRM
description of bit 9.10 adds the word "prefer".

> So, I like the idea but it should not be tied to SyncE only.

Something like this?

   | ethtool property        | effect             |
   |-------------------------+--------------------|
   | synce-mode = none       | 9.12 = 0           |
   | synce-mode = master     | 9.12 = 1, 9.11 = 1 |
   | synce-mode = slave      | 9.12 = 1, 9.11 = 0 |
   |                         |                    |
   | port-type = multiport   | 9.10 = 1           |
   | port-type = single-port | 9.10 = 0           |

Thanks,
Richard