Re: RFC: phylink: disable PHY autonomous EEE when MAC manages LPI

[Nicolai Buchwitz <nb@tipi-net.de>]

On 1.4.2026 18:02, Russell King (Oracle) wrote:
> On Wed, Apr 01, 2026 at 05:38:23PM +0200, Andrew Lunn wrote:
>> On Wed, Apr 01, 2026 at 04:05:32PM +0100, Russell King (Oracle) wrote:
>> > On Wed, Apr 01, 2026 at 03:11:24PM +0200, Andrew Lunn wrote:
>> > > > Thanks Russell and Andrew. You're both heading in the same direction,
>> > > > so to make sure I understand correctly:
>> > > >
>> > > > 1. Add a new phylib interface (separate from phy_ethtool_set_eee) to
>> > > >    control PHY-autonomous EEE, e.g. phy_set_autonomous_eee(phydev,
>> > > >    enable) and phy_get_autonomous_eee(phydev) to query the current
>> > > >    state.
>> > >
>> > > In the end, we want the MAC driver using phylib to just call the
>> > > phylib methods for configuring EEE, and the MAC driver should not care
>> > > if EEE is actually implemented in the PHY or the MAC. The adjust_link
>> > > callback would simply not enable LPI if the PHY is doing EEE.
>> >
>> > This won't work.
>> >
>> > If we mask out eee.tx_lpi_enabled when calling into phylib to tell
>> > phylib drivers to disable SmartEEE (that's what I'm calling it here
>> > because it's easier to type)),
>> 
>> We need phylib to handle some state information. Are we doing MAC EEE
>> or SmartEEE? We can then set phydev->enable_tx_lpi == True to indicate
>> if the MAC should be sending LPI indications, if and only if the
>> phylib knows we are doing MAC EEE and it should be enabled because the
>> user said so.
> 
> Right, and that's why I suggested phy_disable_autonomous_eee() to tell
> phylib to disable SmartEEE/autonomous EEE support at the PHY 
> independent
> of phy_ethtool_set_eee().
> 
> I was also suggesting that there's eventually a complementary function
> that says basically "please enable SmartEEE" because we may have phy
> drivers that disable it today.
> 
> In absence of either call, phy drivers need to maintain their current
> state.
> 
>> However, i think this is down the road. If the MAC driver calls
>> phy_support_eee(), we should call the SmartEEE disable method of the
>> PHY driver. When we add support for SmartEEE then we need this
>> additional state information.
> 
> That also works for me.

Thanks both. So if I understand correctly:

1. Add a .disable_autonomous_eee callback to struct phy_driver

2. Call it from phy_support_eee() so MAC drivers don't need to know
    or care whether the PHY does (autonomous|smart)eee

3. BCM54xx (AutogrEEEn) and RTL8211F as first users

4. No enable counterpart for now. PHY drivers maintain their current
    default behavior unless phy_support_eee() is called.

Sounds good. Sorting out the warts of (autonomous|smart)eee will be
iterative anyway, so starting with just the disable path makes sense
(and hopefully will make setups a bit less broken than they were with
both fighting for LPI).

I'll put the RFC patches together.

Nicolai