Re: [PATCH net-next 10/11] net: dsa: mv88e6xxx: remove EEE support

From: Florian Fainelli
Date: Tue Aug 01 2017 - 14:53:26 EST

On 08/01/2017 10:27 AM, Andrew Lunn wrote:
>> If the MAC does not support EEE but the PHY does I think you can still
>> allow EEE to be advertised and enabled, you just won't have the MAC be
>> able to leverage the power savings that EEE brings. AFAICT this is still
>> a valid mode whereby the PHY is put in a lower power mode, just not the
>> whole transmit path (MAC + PHY).
> Hi Florian
> I read a couple of datasheets for a few phys doing EEE. Both said the
> same, the MAC has to indicate to the PHY when low power should be
> entered and existed. The PHY itself does not appear to do anything on
> its own.

Oh you are right, the LPI signal has to come from the MAC for the PHY to
decide how to do the idle signaling, my bad.

> It would be good to read the standards about this. But i don't think
> we should tell userspace EEE is enabled, if the PHY has it enabled,
> but the MAC is not capable and hence EEE is not actually being used at
> all.