net: phy: Support speed selection for PHY loopback

phy_loopback() leaves it to the PHY driver to select the speed of the
loopback mode. Thus, the speed of the loopback mode depends on the PHY
driver in use.

Add support for speed selection to phy_loopback() to enable loopback
with defined speeds. Ensure that link up is signaled if speed changes
as speed is not allowed to change during link up. Link down and up is
necessary for a new speed.

Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Link: https://patch.msgid.link/20250312203010.47429-3-gerhard@engleder-embedded.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/engleder/tsnep_main.c b/drivers/net/ethernet/engleder/tsnep_main.c
index 3de4cb0..7a9fe07 100644 (file)
--- a/drivers/net/ethernet/engleder/tsnep_main.c
+++ b/drivers/net/ethernet/engleder/tsnep_main.c
@@ -223,7 +223,7 @@ static int tsnep_phy_loopback(struct tsnep_adapter *adapter, bool enable)
 {
        int retval;
 
-       retval = phy_loopback(adapter->phydev, enable);
+       retval = phy_loopback(adapter->phydev, enable, 0);
 
        /* PHY link state change is not signaled if loopback is enabled, it
         * would delay a working loopback anyway, let's ensure that loopback

diff --git a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
index 6c458f0..60a586a 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
@@ -266,9 +266,9 @@ static int hns_nic_config_phy_loopback(struct phy_device *phy_dev, u8 en)
                if (err)
                        goto out;
 
-               err = phy_loopback(phy_dev, true);
+               err = phy_loopback(phy_dev, true, 0);
        } else {
-               err = phy_loopback(phy_dev, false);
+               err = phy_loopback(phy_dev, false, 0);
                if (err)
                        goto out;
 

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
index 8c736a0..92f9b8e 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
@@ -7875,7 +7875,7 @@ static int hclge_enable_phy_loopback(struct hclge_dev *hdev,
        if (ret)
                return ret;
 
-       return phy_loopback(phydev, true);
+       return phy_loopback(phydev, true, 0);
 }
 
 static int hclge_disable_phy_loopback(struct hclge_dev *hdev,
@@ -7883,7 +7883,7 @@ static int hclge_disable_phy_loopback(struct hclge_dev *hdev,
 {
        int ret;
 
-       ret = phy_loopback(phydev, false);
+       ret = phy_loopback(phydev, false, 0);
        if (ret)
                return ret;
 

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_mdio.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_mdio.c
index 8007965..9a456eb 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_mdio.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_mdio.c
@@ -258,7 +258,7 @@ void hclge_mac_start_phy(struct hclge_dev *hdev)
        if (!phydev)
                return;
 
-       phy_loopback(phydev, false);
+       phy_loopback(phydev, false, 0);
 
        phy_start(phydev);
 }

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
index 3ca1c2a..a01bc39 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
@@ -382,14 +382,14 @@ static int stmmac_test_phy_loopback(struct stmmac_priv *priv)
        if (!priv->dev->phydev)
                return -EOPNOTSUPP;
 
-       ret = phy_loopback(priv->dev->phydev, true);
+       ret = phy_loopback(priv->dev->phydev, true, 0);
        if (ret)
                return ret;
 
        attr.dst = priv->dev->dev_addr;
        ret = __stmmac_test_loopback(priv, &attr);
 
-       phy_loopback(priv->dev->phydev, false);
+       phy_loopback(priv->dev->phydev, false, 0);
        return ret;
 }
 
@@ -1985,7 +1985,7 @@ void stmmac_selftest_run(struct net_device *dev,
                case STMMAC_LOOPBACK_PHY:
                        ret = -EOPNOTSUPP;
                        if (dev->phydev)
-                               ret = phy_loopback(dev->phydev, true);
+                               ret = phy_loopback(dev->phydev, true, 0);
                        if (!ret)
                                break;
                        fallthrough;
@@ -2018,7 +2018,7 @@ void stmmac_selftest_run(struct net_device *dev,
                case STMMAC_LOOPBACK_PHY:
                        ret = -EOPNOTSUPP;
                        if (dev->phydev)
-                               ret = phy_loopback(dev->phydev, false);
+                               ret = phy_loopback(dev->phydev, false, 0);
                        if (!ret)
                                break;
                        fallthrough;

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 562acde..13df284 100644 (file)
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1707,6 +1707,93 @@ void phy_mac_interrupt(struct phy_device *phydev)
 }
 EXPORT_SYMBOL(phy_mac_interrupt);
 
+/**
+ * phy_loopback - Configure loopback mode of PHY
+ * @phydev: target phy_device struct
+ * @enable: enable or disable loopback mode
+ * @speed: enable loopback mode with speed
+ *
+ * Configure loopback mode of PHY and signal link down and link up if speed is
+ * changing.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int phy_loopback(struct phy_device *phydev, bool enable, int speed)
+{
+       bool link_up = false;
+       int ret = 0;
+
+       if (!phydev->drv)
+               return -EIO;
+
+       mutex_lock(&phydev->lock);
+
+       if (enable && phydev->loopback_enabled) {
+               ret = -EBUSY;
+               goto out;
+       }
+
+       if (!enable && !phydev->loopback_enabled) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       if (enable) {
+               /*
+                * Link up is signaled with a defined speed. If speed changes,
+                * then first link down and after that link up needs to be
+                * signaled.
+                */
+               if (phydev->link && phydev->state == PHY_RUNNING) {
+                       /* link is up and signaled */
+                       if (speed && phydev->speed != speed) {
+                               /* signal link down and up for new speed */
+                               phydev->link = false;
+                               phydev->state = PHY_NOLINK;
+                               phy_link_down(phydev);
+
+                               link_up = true;
+                       }
+               } else {
+                       /* link is not signaled */
+                       if (speed) {
+                               /* signal link up for new speed */
+                               link_up = true;
+                       }
+               }
+       }
+
+       if (phydev->drv->set_loopback)
+               ret = phydev->drv->set_loopback(phydev, enable, speed);
+       else
+               ret = genphy_loopback(phydev, enable, speed);
+
+       if (ret) {
+               if (enable) {
+                       /* try to restore link if enabling loopback fails */
+                       if (phydev->drv->set_loopback)
+                               phydev->drv->set_loopback(phydev, false, 0);
+                       else
+                               genphy_loopback(phydev, false, 0);
+               }
+
+               goto out;
+       }
+
+       if (link_up) {
+               phydev->link = true;
+               phydev->state = PHY_RUNNING;
+               phy_link_up(phydev);
+       }
+
+       phydev->loopback_enabled = enable;
+
+out:
+       mutex_unlock(&phydev->lock);
+       return ret;
+}
+EXPORT_SYMBOL(phy_loopback);
+
 /**
  * phy_eee_tx_clock_stop_capable() - indicate whether the MAC can stop tx clock
  * @phydev: target phy_device struct

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 09864c9..675fbd2 100644 (file)
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1818,41 +1818,6 @@ int phy_resume(struct phy_device *phydev)
 }
 EXPORT_SYMBOL(phy_resume);
 
-int phy_loopback(struct phy_device *phydev, bool enable)
-{
-       int ret = 0;
-
-       if (!phydev->drv)
-               return -EIO;
-
-       mutex_lock(&phydev->lock);
-
-       if (enable && phydev->loopback_enabled) {
-               ret = -EBUSY;
-               goto out;
-       }
-
-       if (!enable && !phydev->loopback_enabled) {
-               ret = -EINVAL;
-               goto out;
-       }
-
-       if (phydev->drv->set_loopback)
-               ret = phydev->drv->set_loopback(phydev, enable, 0);
-       else
-               ret = genphy_loopback(phydev, enable, 0);
-
-       if (ret)
-               goto out;
-
-       phydev->loopback_enabled = enable;
-
-out:
-       mutex_unlock(&phydev->lock);
-       return ret;
-}
-EXPORT_SYMBOL(phy_loopback);
-
 /**
  * phy_reset_after_clk_enable - perform a PHY reset if needed
  * @phydev: target phy_device struct

diff --git a/include/linux/phy.h b/include/linux/phy.h
index 1c05158..60d3b88 100644 (file)
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1808,7 +1808,7 @@ int phy_init_hw(struct phy_device *phydev);
 int phy_suspend(struct phy_device *phydev);
 int phy_resume(struct phy_device *phydev);
 int __phy_resume(struct phy_device *phydev);
-int phy_loopback(struct phy_device *phydev, bool enable);
+int phy_loopback(struct phy_device *phydev, bool enable, int speed);
 int phy_sfp_connect_phy(void *upstream, struct phy_device *phy);
 void phy_sfp_disconnect_phy(void *upstream, struct phy_device *phy);
 void phy_sfp_attach(void *upstream, struct sfp_bus *bus);

diff --git a/net/core/selftests.c b/net/core/selftests.c
index 8f801e6..e99ae98 100644 (file)
--- a/net/core/selftests.c
+++ b/net/core/selftests.c
@@ -299,7 +299,7 @@ static int net_test_phy_loopback_enable(struct net_device *ndev)
        if (!ndev->phydev)
                return -EOPNOTSUPP;
 
-       return phy_loopback(ndev->phydev, true);
+       return phy_loopback(ndev->phydev, true, 0);
 }
 
 static int net_test_phy_loopback_disable(struct net_device *ndev)
@@ -307,7 +307,7 @@ static int net_test_phy_loopback_disable(struct net_device *ndev)
        if (!ndev->phydev)
                return -EOPNOTSUPP;
 
-       return phy_loopback(ndev->phydev, false);
+       return phy_loopback(ndev->phydev, false, 0);
 }
 
 static int net_test_phy_loopback_udp(struct net_device *ndev)