From b94773dc4df7026a6f29b2c65e96e88d29cdb576 Mon Sep 17 00:00:00 2001 From: Alexander Sverdlin Date: Tue, 22 Sep 2026 09:52:46 +0200 Subject: [PATCH] net: phy: intel-xway: workaround 100BASE-TX Link-Up issue MaxLinear GSW12x/GSW14x Ethernet Switch Errata Sheet states: "An issue has been sporadically observed after device power-on on the first link-up attempt in 100BASE-TX mode resulting in either the link-up taking a long time, or failing to link-up altogether... Workaround: After power-on, enable Cable Diagnostic Mode for all ports and disable it..." Implement the proposed workaround unconditionally in the Intel XWAY driver (MaxLinear GSW1xx switches incorporate Intel XWAY PHYs) because the diagnostic bits have the same meaning even in older integral PHYs such as GPY111/PEF7071/PHY11G. So it's not clear how to distinguish the affected newer integrated PHYs, but the workaround should not hurt the older PHYs. Cc: stable@vger.kernel.org Fixes: 22335939ec90 ("net: dsa: add driver for MaxLinear GSW1xx switch family") Signed-off-by: Alexander Sverdlin Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/20260922075251.23386-1-alexander.sverdlin@siemens.com Signed-off-by: Jakub Kicinski --- drivers/net/phy/intel-xway.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/intel-xway.c b/drivers/net/phy/intel-xway.c index afbcec711744..3cee31bb931f 100644 --- a/drivers/net/phy/intel-xway.c +++ b/drivers/net/phy/intel-xway.c @@ -16,6 +16,11 @@ #define XWAY_MDIO_ISTAT 0x1A /* interrupt status */ #define XWAY_MDIO_LED 0x1B /* led control */ +#define XWAY_MDIO_GCTRL_TM_MASK GENMASK(15, 13) +#define XWAY_MDIO_GCTRL_TM(mode) FIELD_PREP(XWAY_MDIO_GCTRL_TM_MASK, (mode)) +#define XWAY_MDIO_GCTRL_TM_NOP XWAY_MDIO_GCTRL_TM(0) /* Normal operation */ +#define XWAY_MDIO_GCTRL_TM_CDIAG XWAY_MDIO_GCTRL_TM(6) /* Cable diagnostics */ + #define XWAY_MDIO_ERRCNT_SEL GENMASK(11, 8) #define XWAY_MDIO_ERRCNT_COUNT GENMASK(7, 0) #define XWAY_MDIO_ERRCNT_SEL_RXERR 0 @@ -326,6 +331,28 @@ static int xway_gphy_probe(struct phy_device *phydev) return 0; } +static int xway_11g_int_config_init(struct phy_device *phydev) +{ + int err; + + /* An issue has been sporadically observed after device power-on on the + * first link-up attempt in 100BASE-TX mode resulting in either the + * link-up taking a long time, or failing to link-up altogether. + * + * Workaround: + * After power-on, enable Cable Diagnostic Mode for all ports and + * disable it. + */ + err = phy_modify(phydev, MII_CTRL1000, XWAY_MDIO_GCTRL_TM_MASK, XWAY_MDIO_GCTRL_TM_CDIAG); + if (err) + return err; + err = phy_modify(phydev, MII_CTRL1000, XWAY_MDIO_GCTRL_TM_MASK, XWAY_MDIO_GCTRL_TM_NOP); + if (err) + return err; + + return xway_gphy_config_init(phydev); +} + static int xway_gphy14_config_aneg(struct phy_device *phydev) { int reg, err; @@ -735,7 +762,7 @@ static struct phy_driver xway_gphy[] = { .phy_id_mask = 0xffffffff, .name = "Intel XWAY PHY11G (xRX v1.2 integrated)", /* PHY_GBIT_FEATURES */ - .config_init = xway_gphy_config_init, + .config_init = xway_11g_int_config_init, .probe = xway_gphy_probe, .handle_interrupt = xway_gphy_handle_interrupt, .config_intr = xway_gphy_config_intr,