net: usb: smsc95xx: add support for ethtool pause parameters

Implement ethtool .get_pauseparam and .set_pauseparam handlers for
configuring flow control on smsc95xx. The driver now supports enabling
or disabling transmit and receive pause frames, with or without
autonegotiation. Pause settings are applied during link-up based on
current PHY state and user configuration.

Previously, the driver used phy_get_pause() during link-up handling,
but lacked initialization and an ethtool interface to configure pause
modes. As a result, flow control support was effectively non-functional.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250718075157.297923-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index 8e82184be5e7d9954b83aae904a37bb7eda175bb..de733e0488bf79f916860a5ef94e0c3ad1a734cc 100644 (file)
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -63,6 +63,9 @@ struct smsc95xx_priv {
        u32 hash_hi;
        u32 hash_lo;
        u32 wolopts;
+       bool pause_rx;
+       bool pause_tx;
+       bool pause_autoneg;
        spinlock_t mac_cr_lock;
        u8 features;
        u8 suspend_flags;
@@ -537,16 +540,23 @@ static void smsc95xx_set_multicast(struct net_device *netdev)
 
 static int smsc95xx_phy_update_flowcontrol(struct usbnet *dev)
 {
-       u32 flow = 0, afc_cfg;
        struct smsc95xx_priv *pdata = dev->driver_priv;
-       bool tx_pause, rx_pause;
+       u32 flow = 0, afc_cfg;
 
        int ret = smsc95xx_read_reg(dev, AFC_CFG, &afc_cfg);
        if (ret < 0)
                return ret;
 
        if (pdata->phydev->duplex == DUPLEX_FULL) {
-               phy_get_pause(pdata->phydev, &tx_pause, &rx_pause);
+               bool tx_pause, rx_pause;
+
+               if (pdata->phydev->autoneg == AUTONEG_ENABLE &&
+                   pdata->pause_autoneg) {
+                       phy_get_pause(pdata->phydev, &tx_pause, &rx_pause);
+               } else {
+                       tx_pause = pdata->pause_tx;
+                       rx_pause = pdata->pause_rx;
+               }
 
                if (rx_pause)
                        flow = 0xFFFF0002;
@@ -772,6 +782,55 @@ static int smsc95xx_ethtool_get_sset_count(struct net_device *ndev, int sset)
        }
 }
 
+static void smsc95xx_get_pauseparam(struct net_device *ndev,
+                                   struct ethtool_pauseparam *pause)
+{
+       struct smsc95xx_priv *pdata;
+       struct usbnet *dev;
+
+       dev = netdev_priv(ndev);
+       pdata = dev->driver_priv;
+
+       pause->autoneg = pdata->pause_autoneg;
+       pause->rx_pause = pdata->pause_rx;
+       pause->tx_pause = pdata->pause_tx;
+}
+
+static int smsc95xx_set_pauseparam(struct net_device *ndev,
+                                  struct ethtool_pauseparam *pause)
+{
+       bool pause_autoneg_rx, pause_autoneg_tx;
+       struct smsc95xx_priv *pdata;
+       struct phy_device *phydev;
+       struct usbnet *dev;
+
+       dev = netdev_priv(ndev);
+       pdata = dev->driver_priv;
+       phydev = ndev->phydev;
+
+       if (!phydev)
+               return -ENODEV;
+
+       pdata->pause_rx = pause->rx_pause;
+       pdata->pause_tx = pause->tx_pause;
+       pdata->pause_autoneg = pause->autoneg;
+
+       if (pause->autoneg) {
+               pause_autoneg_rx = pause->rx_pause;
+               pause_autoneg_tx = pause->tx_pause;
+       } else {
+               pause_autoneg_rx = false;
+               pause_autoneg_tx = false;
+       }
+
+       phy_set_asym_pause(ndev->phydev, pause_autoneg_rx, pause_autoneg_tx);
+       if (phydev->link && (!pause->autoneg ||
+                            phydev->autoneg == AUTONEG_DISABLE))
+               smsc95xx_mac_update_fullduplex(dev);
+
+       return 0;
+}
+
 static const struct ethtool_ops smsc95xx_ethtool_ops = {
        .get_link       = smsc95xx_get_link,
        .nway_reset     = phy_ethtool_nway_reset,
@@ -791,6 +850,8 @@ static const struct ethtool_ops smsc95xx_ethtool_ops = {
        .self_test      = net_selftest,
        .get_strings    = smsc95xx_ethtool_get_strings,
        .get_sset_count = smsc95xx_ethtool_get_sset_count,
+       .get_pauseparam = smsc95xx_get_pauseparam,
+       .set_pauseparam = smsc95xx_set_pauseparam,
 };
 
 static int smsc95xx_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
@@ -1227,6 +1288,11 @@ static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
        dev->net->max_mtu = ETH_DATA_LEN;
        dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;
 
+       pdata->pause_tx = true;
+       pdata->pause_rx = true;
+       pdata->pause_autoneg = true;
+       phy_support_asym_pause(pdata->phydev);
+
        ret = phy_connect_direct(dev->net, pdata->phydev,
                                 &smsc95xx_handle_link_change,
                                 PHY_INTERFACE_MODE_MII);