net: phy: Support speed selection for PHY loopback
authorGerhard Engleder <gerhard@engleder-embedded.com>
Wed, 12 Mar 2025 20:30:07 +0000 (21:30 +0100)
committerPaolo Abeni <pabeni@redhat.com>
Thu, 20 Mar 2025 07:45:08 +0000 (08:45 +0100)
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>
drivers/net/ethernet/engleder/tsnep_main.c
drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_mdio.c
drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
drivers/net/phy/phy.c
drivers/net/phy/phy_device.c
include/linux/phy.h
net/core/selftests.c

index 3de4cb06e2668fbdd2c8623960a2034b881800ce..7a9fe0719f8cc0e1ec44bae5d761bee4a6fa5306 100644 (file)
@@ -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
index 6c458f037262fd85f816b5ddb81e7675c033340c..60a586a951a02129e632e9e4a9dacabd694012e4 100644 (file)
@@ -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;
 
index 8c736a069eeb495f54f121ec817ceaf7fd28ad9f..92f9b8ec76d9fd0b1af3b6fd4760787ebdce290f 100644 (file)
@@ -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;
 
index 80079657afebe0add970be55425deaa87b46e3b4..9a456ebf9b7cd39aa293eaf06d2ce598f8ada0aa 100644 (file)
@@ -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);
 }
index 3ca1c2a816ff18e244990354b3a2f9ba5f37f4da..a01bc394d1ac467ba15d2068629c7bbabc05ecc6 100644 (file)
@@ -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;
index 562acde8922494c92f5ac07f76a6b6c5d68d9586..13df28445f0201dda26b9e4a2819feacd4977094 100644 (file)
@@ -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
index 09864c9635ace42e53ff411f37b845d9c7877500..675fbd225378796085cdc6c92ee2d7e9bff0b6f6 100644 (file)
@@ -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
index 1c05158e94388514628e3cd39002e329a465d6c0..60d3b8860ea2605af746db84920ef2f0a193a713 100644 (file)
@@ -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);
index 8f801e6e3b91b4cbb2886a2f0a5b478d48ed6246..e99ae983fca9bb57b6955bf0b6fb365f93e4445f 100644 (file)
@@ -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)