Re: [PATCH net] net: bcmgenet: Fix EEE implementation

[Florian Fainelli]

On 6/6/23 15:02, Russell King (Oracle) wrote:
> On Tue, Jun 06, 2023 at 02:43:47PM -0700, Florian Fainelli wrote:
> > We had a number of short comings:
> >
> > - EEE must be re-evaluated whenever the state machine detects a link
> >    change as wight be switching from a link partner with EEE
> >    enabled/disabled
> >
> > - tx_lpi_enabled controls whether EEE should be enabled/disabled for the
> >    transmit path, which applies to the TBUF block
> >
> > - We do not need to forcibly enable EEE upon system resume, as the PHY
> >    state machine will trigger a link event that will do that, too
> >
> > Fixes: 6ef398ea60d9 ("net: bcmgenet: add EEE support")
> > Signed-off-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
> > ---
> > netdev maintainers, please do not apply without Andrew, Russell and
> > Oleksij reviewing first since this relates to the on-going EEE rework
> > from Andrew.
>
> Hi Florian,
>
> Please could you include some information on the UMAC_EEE_CTRL EEE_EN
> bit - is this like the main switch for EEE which needs to be set
> along with the bits in the tbuf register for the transmit side to
> signal LPI?

EEE_EN is described as:

If set, the TX LPI policy control engine is enabled and the MAC inserts 
LPI_idle codes if the link is idle. The rx_lpi_detect assertion is 
independent of this configuration.

in the RBUF, EEE_EN is described as:

1: to enable Energy Efficient feature between Unimac and PHY for Rx Path

and in the TBUF, EEE_EN is described as:

1: to enable Energy Efficient feature between Unimac and PHY for Tx Path

The documentation is unfortunately scare about how these two signals 
connect :/
--
Florian

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