Re: [PATCH net-next v1 1/2] net: asix: ax88772: migrate to phylink

[Paolo Abeni <pabeni@redhat.com>]

On Sat, 2022-07-23 at 19:47 +0200, Oleksij Rempel wrote:
> There are some exotic ax88772 based devices which may require
> functionality provide by the phylink framework. For example:
> - US100A20SFP, USB 2.0 auf LWL Converter with SFP Cage
> - AX88772B USB to 100Base-TX Ethernet (with RMII) demo board, where it
>   is possible to switch between internal PHY and external RMII based
>   connection.
> 
> So, convert this driver to phylink as soon as possible.
> 
> Tested with:
> - AX88772A + internal PHY
> - AX88772B + external DP83TD510E T1L PHY
> 
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---
>  drivers/net/usb/Kconfig        |   2 +-
>  drivers/net/usb/asix.h         |   3 +
>  drivers/net/usb/asix_devices.c | 123 ++++++++++++++++++++++++++++-----
>  3 files changed, 110 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig
> index e62fc4f2aee0..3d46b5f9287a 100644
> --- a/drivers/net/usb/Kconfig
> +++ b/drivers/net/usb/Kconfig
> @@ -168,7 +168,7 @@ config USB_NET_AX8817X
>  	tristate "ASIX AX88xxx Based USB 2.0 Ethernet Adapters"
>  	depends on USB_USBNET
>  	select CRC32
> -	select PHYLIB
> +	select PHYLINK
>  	select AX88796B_PHY
>  	imply NET_SELFTESTS
>  	default y
> diff --git a/drivers/net/usb/asix.h b/drivers/net/usb/asix.h
> index 21c1ca275cc4..74162190bccc 100644
> --- a/drivers/net/usb/asix.h
> +++ b/drivers/net/usb/asix.h
> @@ -27,6 +27,7 @@
>  #include <linux/if_vlan.h>
>  #include <linux/phy.h>
>  #include <net/selftests.h>
> +#include <linux/phylink.h>
>  
>  #define DRIVER_VERSION "22-Dec-2011"
>  #define DRIVER_NAME "asix"
> @@ -185,6 +186,8 @@ struct asix_common_private {
>  	struct mii_bus *mdio;
>  	struct phy_device *phydev;
>  	struct phy_device *phydev_int;
> +	struct phylink *phylink;
> +	struct phylink_config phylink_config;
>  	u16 phy_addr;
>  	bool embd_phy;
>  	u8 chipcode;
> diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
> index 5b5eb630c4b7..3f93bc46a7eb 100644
> --- a/drivers/net/usb/asix_devices.c
> +++ b/drivers/net/usb/asix_devices.c
> @@ -327,6 +327,12 @@ static int ax88772_reset(struct usbnet *dev)
>  	struct asix_common_private *priv = dev->driver_priv;
>  	int ret;
>  
> +	ret = phylink_connect_phy(priv->phylink, priv->phydev);
> +	if (ret) {
> +		netdev_err(dev->net, "Could not connect PHY\n");
> +		return ret;
> +	}

Don't you need to additionally call phylink_disconnect_phy() in later
error paths? why?

> +
>  	/* Rewrite MAC address */
>  	ether_addr_copy(data->mac_addr, dev->net->dev_addr);
>  	ret = asix_write_cmd(dev, AX_CMD_WRITE_NODE_ID, 0, 0,
> @@ -343,7 +349,7 @@ static int ax88772_reset(struct usbnet *dev)
>  	if (ret < 0)
>  		goto out;
>  
> -	phy_start(priv->phydev);
> +	phylink_start(priv->phylink);
>  
>  	return 0;
>  
> @@ -590,8 +596,11 @@ static void ax88772_suspend(struct usbnet *dev)
>  	struct asix_common_private *priv = dev->driver_priv;
>  	u16 medium;
>  
> -	if (netif_running(dev->net))
> -		phy_stop(priv->phydev);
> +	if (netif_running(dev->net)) {
> +		rtnl_lock();
> +		phylink_suspend(priv->phylink, false);
> +		rtnl_unlock();
> +	}
>  
>  	/* Stop MAC operation */
>  	medium = asix_read_medium_status(dev, 1);
> @@ -622,8 +631,11 @@ static void ax88772_resume(struct usbnet *dev)
>  		if (!priv->reset(dev, 1))
>  			break;
>  
> -	if (netif_running(dev->net))
> -		phy_start(priv->phydev);
> +	if (netif_running(dev->net)) {
> +		rtnl_lock();
> +		phylink_resume(priv->phylink);
> +		rtnl_unlock();
> +	}
>  }
>  
>  static int asix_resume(struct usb_interface *intf)
> @@ -659,7 +671,6 @@ static int ax88772_init_mdio(struct usbnet *dev)
>  static int ax88772_init_phy(struct usbnet *dev)
>  {
>  	struct asix_common_private *priv = dev->driver_priv;
> -	int ret;
>  
>  	priv->phydev = mdiobus_get_phy(priv->mdio, priv->phy_addr);
>  	if (!priv->phydev) {
> @@ -667,13 +678,6 @@ static int ax88772_init_phy(struct usbnet *dev)
>  		return -ENODEV;
>  	}
>  
> -	ret = phy_connect_direct(dev->net, priv->phydev, &asix_adjust_link,
> -				 PHY_INTERFACE_MODE_INTERNAL);
> -	if (ret) {
> -		netdev_err(dev->net, "Could not connect PHY\n");
> -		return ret;
> -	}
> -
>  	phy_suspend(priv->phydev);
>  	priv->phydev->mac_managed_pm = 1;
>  
> @@ -698,6 +702,89 @@ static int ax88772_init_phy(struct usbnet *dev)
>  	return 0;
>  }
>  
> +static void ax88772_mac_config(struct phylink_config *config, unsigned int mode,
> +			      const struct phylink_link_state *state)
> +{
> +	/* Nothing to do */
> +}
> +
> +static void ax88772_mac_link_down(struct phylink_config *config,
> +				 unsigned int mode, phy_interface_t interface)
> +{
> +	struct usbnet *dev = netdev_priv(to_net_dev(config->dev));
> +
> +	asix_write_medium_mode(dev, 0, 0);
> +	usbnet_link_change(dev, false, false);
> +}
> +
> +static void ax88772_mac_link_up(struct phylink_config *config,
> +			       struct phy_device *phy,
> +			       unsigned int mode, phy_interface_t interface,
> +			       int speed, int duplex,
> +			       bool tx_pause, bool rx_pause)
> +{
> +	struct usbnet *dev = netdev_priv(to_net_dev(config->dev));
> +	u16 m = AX_MEDIUM_AC | AX_MEDIUM_RE;
> +
> +	m |= duplex ? AX_MEDIUM_FD : 0;
> +
> +	switch (speed) {
> +	case SPEED_100:
> +		m |= AX_MEDIUM_PS;
> +		break;
> +	case SPEED_10:
> +		break;
> +	default:
> +		return;
> +	}
> +
> +	if (tx_pause)
> +		m |= AX_MEDIUM_TFC;
> +
> +	if (rx_pause)
> +		m |= AX_MEDIUM_RFC;
> +
> +	asix_write_medium_mode(dev, m, 0);
> +	usbnet_link_change(dev, true, false);
> +}
> +
> +static const struct phylink_mac_ops ax88772_phylink_mac_ops = {
> +	.validate = phylink_generic_validate,
> +	.mac_config = ax88772_mac_config,
> +	.mac_link_down = ax88772_mac_link_down,
> +	.mac_link_up = ax88772_mac_link_up,
> +};
> +
> +static int ax88772_phylink_setup(struct usbnet *dev)
> +{
> +	struct asix_common_private *priv = dev->driver_priv;
> +	phy_interface_t phy_if_mode;
> +	struct phylink *phylink;
> +
> +	priv->phylink_config.dev = &dev->net->dev;
> +	priv->phylink_config.type = PHYLINK_NETDEV;
> +	priv->phylink_config.mac_capabilities = MAC_SYM_PAUSE | MAC_ASYM_PAUSE |
> +		MAC_10 | MAC_100;
> +
> +	__set_bit(PHY_INTERFACE_MODE_INTERNAL,
> +		  priv->phylink_config.supported_interfaces);
> +	__set_bit(PHY_INTERFACE_MODE_RMII,
> +		  priv->phylink_config.supported_interfaces);
> +
> +	if (priv->embd_phy)
> +		phy_if_mode = PHY_INTERFACE_MODE_INTERNAL;
> +	else
> +		phy_if_mode = PHY_INTERFACE_MODE_RMII;
> +
> +	phylink = phylink_create(&priv->phylink_config, dev->net->dev.fwnode,
> +				 phy_if_mode, &ax88772_phylink_mac_ops);
> +	if (IS_ERR(phylink))
> +		return PTR_ERR(phylink);
> +
> +	priv->phylink = phylink;

Who will call phylink_destroy() on priv->phylink? It looks like you are
leaking it ?!?

Thanks!

Paolo