RE: [PATCH net-next v5 2/8] net: phy: Add phydev->enable_tx_lpi to simplify adjust link callbacks

[Wei Fang]

> -----Original Message-----
> From: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
> Sent: 2024年2月21日 14:21
> To: Wei Fang <wei.fang@xxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>;
> Eric Dumazet <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>;
> Paolo Abeni <pabeni@xxxxxxxxxx>; Andrew Lunn <andrew@xxxxxxx>;
> Heiner Kallweit <hkallweit1@xxxxxxxxx>; Russell King
> <linux@xxxxxxxxxxxxxxx>
> Cc: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>; Oleksij Rempel
> <o.rempel@xxxxxxxxxxxxxx>; kernel@xxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; Shenwei Wang
> <shenwei.wang@xxxxxxx>; Clark Wang <xiaoning.wang@xxxxxxx>;
> dl-linux-imx <linux-imx@xxxxxxx>
> Subject: [PATCH net-next v5 2/8] net: phy: Add phydev->enable_tx_lpi to
> simplify adjust link callbacks
> 
> From: Andrew Lunn <andrew@xxxxxxx>
> 
> 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 <florian.fainelli@xxxxxxxxxxxx>
> Signed-off-by: Andrew Lunn <andrew@xxxxxxx>
> Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
> ---
> v2 Check for errors from genphy_c45_eee_is_active
> v5: Rename to enable_tx_lpi to fit better with phylink changes
> ---
>  drivers/net/phy/phy.c | 7 +++++++
>  include/linux/phy.h   | 2 ++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index
> 14224e06d69f..a54b1daf5d5f 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;

phydev->enable_tx_lpi = !!err; Is this better?

>  		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);
>  	}
> 
> diff --git a/include/linux/phy.h b/include/linux/phy.h index
> e3ab2c347a59..a880f6d7170e 100644
> --- a/include/linux/phy.h
> +++ b/include/linux/phy.h
> @@ -594,6 +594,7 @@ struct macsec_ops;
>   * @supported_eee: supported PHY EEE linkmodes
>   * @advertising_eee: Currently advertised EEE linkmodes
>   * @eee_enabled: Flag indicating whether the EEE feature is enabled
> + * @enable_tx_lpi: When True, MAC should transmit LPI to PHY
>   * @lp_advertising: Current link partner advertised linkmodes
>   * @host_interfaces: PHY interface modes supported by host
>   * @eee_broken_modes: Energy efficient ethernet modes which should be
> prohibited @@ -713,6 +714,7 @@ struct phy_device {
> 
>  	/* Energy efficient ethernet modes which should be prohibited */
>  	u32 eee_broken_modes;
> +	bool enable_tx_lpi;
> 
>  #ifdef CONFIG_LED_TRIGGER_PHY
>  	struct phy_led_trigger *phy_led_triggers;
> --
> 2.39.2