From: Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com>
Date: Tue, 26 May 2026 14:58:11 +0000 (+0200)
Subject: net: phy: air_an8801: ensure maximum available speed link use
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f6465e36353f4bc03ccb68834527655a25187d81;p=thirdparty%2Flinux.git

net: phy: air_an8801: ensure maximum available speed link use

To ensure that the Airoha AN8801R PHY uses the maximum available link
speed, an additional register write is needed to configure the function
mode for either 1G or 100M/10M operation after link detection.

So, in air_an8801 driver, implement a custom read_status callback, that
after genphy_read_status determines the link speed, sets the bit 0 of
the link mode register (REG_LINK_MODE) if the detected speed is 1Gbps,
or unsets it otherwise.

Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20260526-add-airoha-an8801-support-v5-6-01aea8dee69b@collabora.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/drivers/net/phy/air_an8801.c b/drivers/net/phy/air_an8801.c
index aa24bb182d64..f97c78e43023 100644
--- a/drivers/net/phy/air_an8801.c
+++ b/drivers/net/phy/air_an8801.c
@@ -996,6 +996,41 @@ static int an8801r_config_init(struct phy_device *phydev)
 	return 0;
 }
 
+static int an8801r_read_status(struct phy_device *phydev)
+{
+	int prev_speed, ret;
+	u32 val;
+
+	prev_speed = phydev->speed;
+
+	ret = genphy_read_status(phydev);
+	if (ret)
+		return ret;
+
+	if (!phydev->link) {
+		phydev->speed = SPEED_UNKNOWN;
+		return 0;
+	}
+
+	if (prev_speed != phydev->speed) {
+		/* Ensure that PHY switches to 1G speed when available,
+		 * by configuring the function mode for either 1G or 100M/10M
+		 * operation.
+		 * Therefore, set the link mode register, after read_status
+		 * determines the link speed.
+		 */
+		val = phydev->speed == SPEED_1000 ?
+		      AN8801_BPBUS_LINK_MODE_1000 : 0;
+
+		return an8801_buckpbus_reg_rmw(phydev,
+					       AN8801_BPBUS_REG_LINK_MODE,
+					       AN8801_BPBUS_LINK_MODE_1000,
+					       val);
+	}
+
+	return 0;
+}
+
 static int an8801r_probe(struct phy_device *phydev)
 {
 	struct device *dev = &phydev->mdio.dev;
@@ -1093,6 +1128,7 @@ static struct phy_driver airoha_driver[] = {
 	.suspend		= an8801r_suspend,
 	.resume			= an8801r_resume,
 	.config_aneg		= genphy_config_aneg,
+	.read_status		= an8801r_read_status,
 	.config_intr		= an8801r_config_intr,
 	.handle_interrupt	= an8801r_handle_interrupt,
 	.set_wol		= an8801r_set_wol,