net: phy: Add phydev->enable_tx_lpi to simplify adjust link callbacks

MAC drivers which support EEE need to know the results of the EEE
auto-neg in order to program the hardware to perform EEE or not.  The
oddly named phy_init_eee() can be used to determine this, it returns 0
if EEE should be used, or a negative error code,
e.g. -EOPPROTONOTSUPPORT if the PHY does not support EEE or negotiate
resulted in it not being used.

However, many MAC drivers get this wrong. Add phydev->enable_tx_lpi
which indicates the result of the autoneg for EEE, including if EEE is
administratively disabled with ethtool. The MAC driver can then access
this in the same way as link speed and duplex in the adjust link
callback. If enable_tx_lpi is true, the MAC should send low power
indications and does not need to consider anything else with respect
to EEE.

Reviewed-by: Florian Fainelli <[email protected]>
Signed-off-by: Andrew Lunn <[email protected]>
Signed-off-by: Oleksij Rempel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 14224e06d69f..2bc0a7d51c63 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -983,9 +983,16 @@ static int phy_check_link_status(struct phy_device *phydev)
 	if (phydev->link && phydev->state != PHY_RUNNING) {
 		phy_check_downshift(phydev);
 		phydev->state = PHY_RUNNING;
+		err = genphy_c45_eee_is_active(phydev,
+					       NULL, NULL, NULL);
+		if (err < 0)
+			phydev->enable_tx_lpi = false;
+		else
+			phydev->enable_tx_lpi = !!err;
 		phy_link_up(phydev);
 	} else if (!phydev->link && phydev->state != PHY_NOLINK) {
 		phydev->state = PHY_NOLINK;
+		phydev->enable_tx_lpi = false;
 		phy_link_down(phydev);
 	}