Re: [RFT PATCH 1/2] net: dsa: mv88e6xxx: Add EEE support

[David Miller <davem@davemloft.net>]

From: Guenter Roeck <linux@roeck-us.net>
Date: Mon, 23 Feb 2015 08:26:09 -0800

> +	/* Don't call phy_init_eee for now. It fails if the link is down,
> +	 * but that should not really be a reason to fail configuration.
> +	 */

I think there is some confusion about phy_init_eee().

You invoke it after a link has been established.  Because programming
the MDIO registers that turn on EEE can only be done if the link
is configured in a certain way.

If you look at stmmac, it invokes phy_init_eee() via it's adjust_link
callback passed to phy_connect().  This is basically how I would
expect it to be used, in that any time a link parameter changes we
rerun phy_init_eee() to check the link partner registers, duplex
state, etc.

SXGBE on the other hand seems to not be using phy_init_eee() properly,
it only invokes it once per device open and that makes no sense at all
because then you're stuck with the eee state resulting from the link
state at open time.