Commit 673d455b authored by Oleksij Rempel's avatar Oleksij Rempel Committed by Jakub Kicinski
Browse files

net: usb: lan78xx: Integrate EEE support with phylink LPI API 



Refactor Energy-Efficient Ethernet (EEE) support in the LAN78xx driver to
fully integrate with the phylink Low Power Idle (LPI) API. This includes:

- Replacing direct calls to `phy_ethtool_get_eee` and `phy_ethtool_set_eee`
  with `phylink_ethtool_get_eee` and `phylink_ethtool_set_eee`.
- Implementing `.mac_enable_tx_lpi` and `.mac_disable_tx_lpi` to control
  LPI transitions via phylink.
- Configuring `lpi_timer_default` to align with recommended values from
  LAN7800 documentation.
- ensure EEE is disabled on controller reset

Signed-off-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20250618122602.3156678-6-o.rempel@pengutronix.de


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 297080cf

drivers/net/usb/lan78xx.c

+79 −44
Original line number Diff line number Diff line
@@ -1789,54 +1789,15 @@ static int lan78xx_set_wol(struct net_device *netdev, 
static int lan78xx_get_eee(struct net_device *net, struct ethtool_keee *edata)

{

	struct lan78xx_net *dev = netdev_priv(net);

	struct phy_device *phydev = net->phydev;

	int ret;

	u32 buf;



	ret = usb_autopm_get_interface(dev->intf);

	if (ret < 0)

		return ret;



	ret = phy_ethtool_get_eee(phydev, edata);

	if (ret < 0)

		goto exit;



	ret = lan78xx_read_reg(dev, MAC_CR, &buf);

	if (buf & MAC_CR_EEE_EN_) {

		/* EEE_TX_LPI_REQ_DLY & tx_lpi_timer are same uSec unit */

		ret = lan78xx_read_reg(dev, EEE_TX_LPI_REQ_DLY, &buf);

		edata->tx_lpi_timer = buf;

	} else {

		edata->tx_lpi_timer = 0;

	}



	ret = 0;

exit:

	usb_autopm_put_interface(dev->intf);



	return ret;

	return phylink_ethtool_get_eee(dev->phylink, edata);

}



static int lan78xx_set_eee(struct net_device *net, struct ethtool_keee *edata)

{

	struct lan78xx_net *dev = netdev_priv(net);

	int ret;

	u32 buf;



	ret = usb_autopm_get_interface(dev->intf);

	if (ret < 0)

		return ret;



	ret = phy_ethtool_set_eee(net->phydev, edata);

	if (ret < 0)

		goto out;



	buf = (u32)edata->tx_lpi_timer;

	ret = lan78xx_write_reg(dev, EEE_TX_LPI_REQ_DLY, buf);

out:

	usb_autopm_put_interface(dev->intf);



	return ret;

	return phylink_ethtool_set_eee(dev->phylink, edata);

}



static void lan78xx_get_drvinfo(struct net_device *net,
@@ -2557,10 +2518,62 @@ static void lan78xx_mac_link_up(struct phylink_config *config, 
		   ERR_PTR(ret));

}



/**

 * lan78xx_mac_eee_enable - Enable or disable MAC-side EEE support

 * @dev: LAN78xx device

 * @enable: true to enable EEE, false to disable

 *

 * This function sets or clears the MAC_CR_EEE_EN_ bit to control Energy

 * Efficient Ethernet (EEE) operation. According to current understanding

 * of the LAN7800 documentation, this bit can be modified while TX and RX

 * are enabled. No explicit requirement was found to disable data paths

 * before changing this bit.

 *

 * Return: 0 on success or a negative error code

 */

static int lan78xx_mac_eee_enable(struct lan78xx_net *dev, bool enable)

{

	u32 mac_cr = 0;



	if (enable)

		mac_cr |= MAC_CR_EEE_EN_;



	return lan78xx_update_reg(dev, MAC_CR, MAC_CR_EEE_EN_, mac_cr);

}



static void lan78xx_mac_disable_tx_lpi(struct phylink_config *config)

{

	struct net_device *net = to_net_dev(config->dev);

	struct lan78xx_net *dev = netdev_priv(net);



	lan78xx_mac_eee_enable(dev, false);

}



static int lan78xx_mac_enable_tx_lpi(struct phylink_config *config, u32 timer,

				     bool tx_clk_stop)

{

	struct net_device *net = to_net_dev(config->dev);

	struct lan78xx_net *dev = netdev_priv(net);

	int ret;



	/* Software should only change this field when Energy Efficient

	 * Ethernet Enable (EEEEN) is cleared. We ensure that by clearing

	 * EEEEN during probe, and phylink itself guarantees that

	 * mac_disable_tx_lpi() will have been previously called.

	 */

	ret = lan78xx_write_reg(dev, EEE_TX_LPI_REQ_DLY, timer);

	if (ret < 0)

		return ret;



	return lan78xx_mac_eee_enable(dev, true);

}



static const struct phylink_mac_ops lan78xx_phylink_mac_ops = {

	.mac_config = lan78xx_mac_config,

	.mac_link_down = lan78xx_mac_link_down,

	.mac_link_up = lan78xx_mac_link_up,

	.mac_disable_tx_lpi = lan78xx_mac_disable_tx_lpi,

	.mac_enable_tx_lpi = lan78xx_mac_enable_tx_lpi,

};



/**
@@ -2756,12 +2769,36 @@ static int lan78xx_phylink_setup(struct lan78xx_net *dev) 
	pc->mac_capabilities = MAC_SYM_PAUSE | MAC_ASYM_PAUSE | MAC_10 |

			       MAC_100 | MAC_1000FD;

	pc->mac_managed_pm = true;

	pc->lpi_capabilities = MAC_100FD | MAC_1000FD;

	/*

	 * Default TX LPI (Low Power Idle) request delay count is set to 50us.

	 *

	 * Source: LAN7800 Documentation, DS00001992H, Section 15.1.57, Page 204.

	 *

	 * Reasoning:

	 * According to the application note in the LAN7800 documentation, a

	 * zero delay may negatively impact the TX data path’s ability to

	 * support Gigabit operation. A value of 50us is recommended as a

	 * reasonable default when the part operates at Gigabit speeds,

	 * balancing stability and power efficiency in EEE mode. This delay can

	 * be increased based on performance testing, as EEE is designed for

	 * scenarios with mostly idle links and occasional bursts of full

	 * bandwidth transmission. The goal is to ensure reliable Gigabit

	 * performance without overly aggressive power optimization during

	 * inactive periods.

	 */

	pc->lpi_timer_default = 50;

	pc->eee_enabled_default = true;



	if (dev->chipid == ID_REV_CHIP_ID_7801_)

		phy_interface_set_rgmii(pc->supported_interfaces);

	else

		__set_bit(PHY_INTERFACE_MODE_GMII, pc->supported_interfaces);



	memcpy(dev->phylink_config.lpi_interfaces,

	       dev->phylink_config.supported_interfaces,

	       sizeof(dev->phylink_config.lpi_interfaces));



	phylink = phylink_create(pc, dev->net->dev.fwnode,

				 dev->interface, &lan78xx_phylink_mac_ops);

	if (IS_ERR(phylink))
@@ -2827,8 +2864,6 @@ static int lan78xx_phy_init(struct lan78xx_net *dev) 
		goto phylink_uninit;

	}



	phy_support_eee(phydev);



	ret = lan78xx_configure_leds_from_dt(dev, phydev);

	if (ret < 0)

		goto phylink_uninit;
@@ -3333,7 +3368,7 @@ static int lan78xx_reset(struct lan78xx_net *dev) 
	if (ret < 0)

		return ret;



	buf &= ~(MAC_CR_AUTO_DUPLEX_ | MAC_CR_AUTO_SPEED_);

	buf &= ~(MAC_CR_AUTO_DUPLEX_ | MAC_CR_AUTO_SPEED_ | MAC_CR_EEE_EN_);



	/* LAN7801 only has RGMII mode */

	if (dev->chipid == ID_REV_CHIP_ID_7801_)