Merge branch 'support-loopback-mode-speed-selection'

Gerhard Engleder says:

====================
Support loopback mode speed selection

Previously to commit 6ff3cddc365b ("net: phylib: do not disable autoneg
for fixed speeds >= 1G") it was possible to select the speed of the
loopback mode by configuring a fixed speed before enabling the loopback
mode. Now autoneg is always enabled for >= 1G and a fixed speed of >= 1G
requires successful autoneg. Thus, the speed of the loopback mode depends
on the link partner for >= 1G. There is no technical reason to depend on
the link partner for loopback mode. With this behavior the loopback mode
is less useful for testing.

Allow PHYs to support optional speed selection for the loopback mode.
This support is implemented for the generic loopback support and for PHY
drivers, which obviously support speed selection for loopback mode.
Additionally, loopback support according to the data sheet is added to
the KSZ9031 PHY.

Extend phy_loopback() to signal link up and down if speed changes,
because a new link speed requires link up signalling.

Use this loopback speed selection in the tsnep driver to select the
loopback mode speed depending the previously active speed. User space
tests with 100 Mbps and 1 Gbps loopback are possible again.
====================

Link: https://patch.msgid.link/20250312203010.47429-1-gerhard@engleder-embedded.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

14 files changed, 194 insertions, 100 deletions

diff --git a/drivers/net/ethernet/engleder/tsnep_main.c b/drivers/net/ethernet/engleder/tsnep_main.c
index 3de4cb06e266..625245b0845c 100644
--- a/drivers/net/ethernet/engleder/tsnep_main.c
+++ b/drivers/net/ethernet/engleder/tsnep_main.c
@@ -221,20 +221,19 @@ static void tsnep_phy_link_status_change(struct net_device *netdev)
 
 static int tsnep_phy_loopback(struct tsnep_adapter *adapter, bool enable)
 {
-	int retval;
-
-	retval = phy_loopback(adapter->phydev, enable);
+	int speed;
 
-	/* PHY link state change is not signaled if loopback is enabled, it
-	 * would delay a working loopback anyway, let's ensure that loopback
-	 * is working immediately by setting link mode directly
-	 */
-	if (!retval && enable) {
-		netif_carrier_on(adapter->netdev);
-		tsnep_set_link_mode(adapter);
+	if (enable) {
+		if (adapter->phydev->autoneg == AUTONEG_DISABLE &&
+		    adapter->phydev->speed == SPEED_100)
+			speed = SPEED_100;
+		else
+			speed = SPEED_1000;
+	} else {
+		speed = 0;
 	}
 
-	return retval;
+	return phy_loopback(adapter->phydev, enable, speed);
 }
 
 static int tsnep_phy_open(struct tsnep_adapter *adapter)
diff --git a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
index 6c458f037262..60a586a951a0 100644
--- 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 8c736a069eeb..92f9b8ec76d9 100644
--- 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 80079657afeb..9a456ebf9b7c 100644
--- 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 3ca1c2a816ff..a01bc394d1ac 100644
--- 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/adin1100.c b/drivers/net/phy/adin1100.c
index 6bb469429b9d..bd7a47a903ac 100644
--- a/drivers/net/phy/adin1100.c
+++ b/drivers/net/phy/adin1100.c
@@ -215,8 +215,11 @@ static int adin_resume(struct phy_device *phydev)
 	return adin_set_powerdown_mode(phydev, false);
 }
 
-static int adin_set_loopback(struct phy_device *phydev, bool enable)
+static int adin_set_loopback(struct phy_device *phydev, bool enable, int speed)
 {
+	if (enable && speed)
+		return -EOPNOTSUPP;
+
 	if (enable)
 		return phy_set_bits_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_10T1L_CTRL,
 					BMCR_LOOPBACK);
diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index c1451df430ac..063266cafe9c 100644
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -1009,8 +1009,11 @@ static void dp83867_link_change_notify(struct phy_device *phydev)
 	}
 }
 
-static int dp83867_loopback(struct phy_device *phydev, bool enable)
+static int dp83867_loopback(struct phy_device *phydev, bool enable, int speed)
 {
+	if (enable && speed)
+		return -EOPNOTSUPP;
+
 	return phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK,
 			  enable ? BMCR_LOOPBACK : 0);
 }
diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
index dd254e36ca8a..623292948fa7 100644
--- a/drivers/net/phy/marvell.c
+++ b/drivers/net/phy/marvell.c
@@ -2131,52 +2131,52 @@ static void marvell_get_stats_simple(struct phy_device *phydev,
 		data[i] = marvell_get_stat_simple(phydev, i);
 }
 
-static int m88e1510_loopback(struct phy_device *phydev, bool enable)
+static int m88e1510_loopback(struct phy_device *phydev, bool enable, int speed)
 {
+	u16 bmcr_ctl, mscr2_ctl = 0;
 	int err;
 
-	if (enable) {
-		u16 bmcr_ctl, mscr2_ctl = 0;
+	if (!enable)
+		return genphy_loopback(phydev, enable, 0);
 
-		bmcr_ctl = mii_bmcr_encode_fixed(phydev->speed, phydev->duplex);
-
-		err = phy_write(phydev, MII_BMCR, bmcr_ctl);
-		if (err < 0)
-			return err;
+	if (speed == SPEED_10 || speed == SPEED_100 || speed == SPEED_1000)
+		phydev->speed = speed;
+	else if (speed)
+		return -EINVAL;
 
-		if (phydev->speed == SPEED_1000)
-			mscr2_ctl = BMCR_SPEED1000;
-		else if (phydev->speed == SPEED_100)
-			mscr2_ctl = BMCR_SPEED100;
+	bmcr_ctl = mii_bmcr_encode_fixed(phydev->speed, phydev->duplex);
 
-		err = phy_modify_paged(phydev, MII_MARVELL_MSCR_PAGE,
-				       MII_88E1510_MSCR_2, BMCR_SPEED1000 |
-				       BMCR_SPEED100, mscr2_ctl);
-		if (err < 0)
-			return err;
+	err = phy_write(phydev, MII_BMCR, bmcr_ctl);
+	if (err < 0)
+		return err;
 
-		/* Need soft reset to have speed configuration takes effect */
-		err = genphy_soft_reset(phydev);
-		if (err < 0)
-			return err;
+	if (phydev->speed == SPEED_1000)
+		mscr2_ctl = BMCR_SPEED1000;
+	else if (phydev->speed == SPEED_100)
+		mscr2_ctl = BMCR_SPEED100;
 
-		err = phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK,
-				 BMCR_LOOPBACK);
+	err = phy_modify_paged(phydev, MII_MARVELL_MSCR_PAGE,
+			       MII_88E1510_MSCR_2, BMCR_SPEED1000 |
+			       BMCR_SPEED100, mscr2_ctl);
+	if (err < 0)
+		return err;
 
-		if (!err) {
-			/* It takes some time for PHY device to switch
-			 * into/out-of loopback mode.
-			 */
-			msleep(1000);
-		}
+	/* Need soft reset to have speed configuration takes effect */
+	err = genphy_soft_reset(phydev);
+	if (err < 0)
 		return err;
-	} else {
-		err = phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK, 0);
-		if (err < 0)
-			return err;
 
-		return phy_config_aneg(phydev);
+	err = phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK,
+			 BMCR_LOOPBACK);
+
+	if (!err) {
+		/*
+		 * It takes some time for PHY device to switch into loopback
+		 * mode.
+		 */
+		msleep(1000);
 	}
+	return err;
 }
 
 static int marvell_vct5_wait_complete(struct phy_device *phydev)
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 289e1d56aa65..24882d30f685 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -1032,6 +1032,29 @@ static int ksz9021_config_init(struct phy_device *phydev)
 #define MII_KSZ9031RN_EDPD		0x23
 #define MII_KSZ9031RN_EDPD_ENABLE	BIT(0)
 
+static int ksz9031_set_loopback(struct phy_device *phydev, bool enable,
+				int speed)
+{
+	u16 ctl = BMCR_LOOPBACK;
+	int val;
+
+	if (!enable)
+		return genphy_loopback(phydev, enable, 0);
+
+	if (speed == SPEED_10 || speed == SPEED_100 || speed == SPEED_1000)
+		phydev->speed = speed;
+	else if (speed)
+		return -EINVAL;
+	phydev->duplex = DUPLEX_FULL;
+
+	ctl |= mii_bmcr_encode_fixed(phydev->speed, phydev->duplex);
+
+	phy_write(phydev, MII_BMCR, ctl);
+
+	return phy_read_poll_timeout(phydev, MII_BMSR, val, val & BMSR_LSTATUS,
+				     5000, 500000, true);
+}
+
 static int ksz9031_of_load_skew_values(struct phy_device *phydev,
 				       const struct device_node *of_node,
 				       u16 reg, size_t field_sz,
@@ -5565,6 +5588,7 @@ static struct phy_driver ksphy_driver[] = {
 	.resume		= kszphy_resume,
 	.cable_test_start	= ksz9x31_cable_test_start,
 	.cable_test_get_status	= ksz9x31_cable_test_get_status,
+	.set_loopback	= ksz9031_set_loopback,
 }, {
 	.phy_id		= PHY_ID_LAN8814,
 	.phy_id_mask	= MICREL_PHY_ID_MASK,
diff --git a/drivers/net/phy/mxl-gpy.c b/drivers/net/phy/mxl-gpy.c
index 94d9cb727121..a6cca8d43253 100644
--- a/drivers/net/phy/mxl-gpy.c
+++ b/drivers/net/phy/mxl-gpy.c
@@ -813,7 +813,7 @@ static void gpy_get_wol(struct phy_device *phydev,
 	wol->wolopts = priv->wolopts;
 }
 
-static int gpy_loopback(struct phy_device *phydev, bool enable)
+static int gpy_loopback(struct phy_device *phydev, bool enable, int speed)
 {
 	struct gpy_priv *priv = phydev->priv;
 	u16 set = 0;
@@ -822,6 +822,9 @@ static int gpy_loopback(struct phy_device *phydev, bool enable)
 	if (enable) {
 		u64 now = get_jiffies_64();
 
+		if (speed)
+			return -EOPNOTSUPP;
+
 		/* wait until 3 seconds from last disable */
 		if (time_before64(now, priv->lb_dis_to))
 			msleep(jiffies64_to_msecs(priv->lb_dis_to - now));
@@ -845,15 +848,15 @@ static int gpy_loopback(struct phy_device *phydev, bool enable)
 	return 0;
 }
 
-static int gpy115_loopback(struct phy_device *phydev, bool enable)
+static int gpy115_loopback(struct phy_device *phydev, bool enable, int speed)
 {
 	struct gpy_priv *priv = phydev->priv;
 
 	if (enable)
-		return gpy_loopback(phydev, enable);
+		return gpy_loopback(phydev, enable, speed);
 
 	if (priv->fw_minor > 0x76)
-		return gpy_loopback(phydev, 0);
+		return gpy_loopback(phydev, 0, 0);
 
 	return genphy_soft_reset(phydev);
 }
diff --git a/drivers/net/phy/phy-c45.c b/drivers/net/phy/phy-c45.c
index 0bcbdce38107..8a0ffc3174ec 100644
--- a/drivers/net/phy/phy-c45.c
+++ b/drivers/net/phy/phy-c45.c
@@ -1228,8 +1228,11 @@ int gen10g_config_aneg(struct phy_device *phydev)
 }
 EXPORT_SYMBOL_GPL(gen10g_config_aneg);
 
-int genphy_c45_loopback(struct phy_device *phydev, bool enable)
+int genphy_c45_loopback(struct phy_device *phydev, bool enable, int speed)
 {
+	if (enable && speed)
+		return -EOPNOTSUPP;
+
 	return phy_modify_mmd(phydev, MDIO_MMD_PCS, MDIO_CTRL1,
 			      MDIO_PCS_CTRL1_LOOPBACK,
 			      enable ? MDIO_PCS_CTRL1_LOOPBACK : 0);
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 562acde89224..13df28445f02 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1708,6 +1708,93 @@ 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 3f734e847e8e..675fbd225378 100644
--- 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);
-	else
-		ret = genphy_loopback(phydev, enable);
-
-	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
@@ -2610,12 +2575,18 @@ int genphy_resume(struct phy_device *phydev)
 }
 EXPORT_SYMBOL(genphy_resume);
 
-int genphy_loopback(struct phy_device *phydev, bool enable)
+int genphy_loopback(struct phy_device *phydev, bool enable, int speed)
 {
 	if (enable) {
 		u16 ctl = BMCR_LOOPBACK;
 		int ret, val;
 
+		if (speed == SPEED_10 || speed == SPEED_100 ||
+		    speed == SPEED_1000)
+			phydev->speed = speed;
+		else if (speed)
+			return -EINVAL;
+
 		ctl |= mii_bmcr_encode_fixed(phydev->speed, phydev->duplex);
 
 		phy_modify(phydev, MII_BMCR, ~0, ctl);
diff --git a/drivers/net/phy/xilinx_gmii2rgmii.c b/drivers/net/phy/xilinx_gmii2rgmii.c
index 7c51daecf18e..2024d8ef36d9 100644
--- a/drivers/net/phy/xilinx_gmii2rgmii.c
+++ b/drivers/net/phy/xilinx_gmii2rgmii.c
@@ -64,15 +64,16 @@ static int xgmiitorgmii_read_status(struct phy_device *phydev)
 	return 0;
 }
 
-static int xgmiitorgmii_set_loopback(struct phy_device *phydev, bool enable)
+static int xgmiitorgmii_set_loopback(struct phy_device *phydev, bool enable,
+				     int speed)
 {
 	struct gmii2rgmii *priv = mdiodev_get_drvdata(&phydev->mdio);
 	int err;
 
 	if (priv->phy_drv->set_loopback)
-		err = priv->phy_drv->set_loopback(phydev, enable);
+		err = priv->phy_drv->set_loopback(phydev, enable, speed);
 	else
-		err = genphy_loopback(phydev, enable);
+		err = genphy_loopback(phydev, enable, speed);
 	if (err < 0)
 		return err;