[PATCH net v3 4/4] net: phy: bcm54811: Fix the PHY initialization
From: Kamil Horák - 2N <hidden>
Date: 2025-06-30 11:31:03
Also in:
linux-devicetree, lkml
Subsystem:
broadcom ethernet phy drivers, ethernet phy library, networking drivers, the rest · Maintainers:
Florian Fainelli, Andrew Lunn, Heiner Kallweit, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Reset the bit 12 in PHY's LRE Control register upon initialization. According to the datasheet, this bit must be written to zero after every device reset. Signed-off-by: Kamil Horák - 2N <redacted> --- drivers/net/phy/broadcom.c | 25 +++++++++++++++++++++---- include/linux/brcmphy.h | 1 + 2 files changed, 22 insertions(+), 4 deletions(-)
diff --git a/drivers/net/phy/broadcom.c b/drivers/net/phy/broadcom.c
index 8547983bd72f..a60e58ef90c4 100644
--- a/drivers/net/phy/broadcom.c
+++ b/drivers/net/phy/broadcom.c@@ -667,7 +667,7 @@ static int bcm5481x_read_abilities(struct phy_device *phydev) { struct device_node *np = phydev->mdio.dev.of_node; struct bcm54xx_phy_priv *priv = phydev->priv; - int i, val, err; + int i, val, err, aneg; for (i = 0; i < ARRAY_SIZE(bcm54811_linkmodes); i++) linkmode_clear_bit(bcm54811_linkmodes[i], phydev->supported);
@@ -688,9 +688,19 @@ static int bcm5481x_read_abilities(struct phy_device *phydev) if (val < 0) return val; + /* BCM54811 is not capable of LDS but the corresponding bit + * in LRESR is set to 1 and marked "Ignore" in the datasheet. + * So we must read the bcm54811 as unable to auto-negotiate + * in BroadR-Reach mode. + */ + if (BRCM_PHY_MODEL(phydev) == PHY_ID_BCM54811) + aneg = 0; + else + aneg = val & LRESR_LDSABILITY; + linkmode_mod_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, phydev->supported, - val & LRESR_LDSABILITY); + aneg); linkmode_mod_bit(ETHTOOL_LINK_MODE_100baseT1_Full_BIT, phydev->supported, val & LRESR_100_1PAIR);
@@ -747,8 +757,15 @@ static int bcm54811_config_aneg(struct phy_device *phydev) /* Aneg firstly. */ if (priv->brr_mode) { - /* BCM54811 is only capable of autonegotiation in IEEE mode */ - phydev->autoneg = 0; + /* BCM54811 is only capable of autonegotiation in IEEE mode. + * In BroadR-Reach mode, disable the Long Distance Signaling, + * the BRR mode autoneg as supported in other Broadcom PHYs. + * This bit is marked as "Reserved" and "Default 1, must be + * written to 0 after every device reset" in the datasheet. + */ + ret = phy_modify(phydev, MII_BCM54XX_LRECR, LRECR_LDSEN, 0); + if (ret < 0) + return ret; ret = bcm_config_lre_aneg(phydev, false); } else { ret = genphy_config_aneg(phydev);
diff --git a/include/linux/brcmphy.h b/include/linux/brcmphy.h
index 15c35655f482..115a964f3006 100644
--- a/include/linux/brcmphy.h
+++ b/include/linux/brcmphy.h@@ -137,6 +137,7 @@ #define MII_BCM54XX_AUXCTL_SHDWSEL_MISC 0x07 #define MII_BCM54XX_AUXCTL_SHDWSEL_MISC_WIRESPEED_EN 0x0010 +#define MII_BCM54XX_AUXCTL_SHDWSEL_MISC_RSVD 0x0060 #define MII_BCM54XX_AUXCTL_SHDWSEL_MISC_RGMII_EN 0x0080 #define MII_BCM54XX_AUXCTL_SHDWSEL_MISC_RGMII_SKEW_EN 0x0100 #define MII_BCM54XX_AUXCTL_MISC_FORCE_AMDIX 0x0200
--
2.39.5