From 2b1b8c4c215af7988136401c902338d091d408a1 Mon Sep 17 00:00:00 2001
From: Daniel Golle <daniel@makrotopia.org>
Date: Mon, 3 Apr 2023 01:21:57 +0300
Subject: [PATCH 2/2] net: phy: realtek: disable SGMII in-band AN for 2.5G PHYs
MAC drivers don't use SGMII in-band autonegotiation unless told to do so
in device tree using 'managed = "in-band-status"'. When using MDIO to
access a PHY, in-band-status is unneeded as we have link-status via
MDIO. Switch off SGMII in-band autonegotiation using magic values.
Reported-by: Chen Minqiang <ptpt52@gmail.com>
Reported-by: Chukun Pan <amadeus@jmu.edu.cn>
Reported-by: Yevhen Kolomeiko <jarvis2709@gmail.com>
Tested-by: Yevhen Kolomeiko <jarvis2709@gmail.com>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
drivers/net/phy/realtek.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -883,6 +883,7 @@ static irqreturn_t rtl9000a_handle_inter
static int rtl8221b_config_init(struct phy_device *phydev)
{
u16 option_mode;
+ int val;
switch (phydev->interface) {
case PHY_INTERFACE_MODE_2500BASEX:
@@ -919,6 +920,13 @@ static int rtl8221b_config_init(struct p
break;
}
+ /* Disable SGMII AN */
+ phy_write_mmd(phydev, RTL8221B_MMD_SERDES_CTRL, 0x7588, 0x2);
+ phy_write_mmd(phydev, RTL8221B_MMD_SERDES_CTRL, 0x7589, 0x71d0);
+ phy_write_mmd(phydev, RTL8221B_MMD_SERDES_CTRL, 0x7587, 0x3);
+ phy_read_mmd_poll_timeout(phydev, RTL8221B_MMD_SERDES_CTRL, 0x7587,
+ val, !(val & BIT(0)), 500, 100000, false);
+
return 0;
}