[PATCH net-next v2] net: phy: micrel: Add Fast link failure support for lan8842
From: Horatiu Vultur <horatiu.vultur@microchip.com>
Date: 2025-09-16 09:41:02
Also in:
lkml
Subsystem:
ethernet phy library, networking drivers, the rest · Maintainers:
Andrew Lunn, Heiner Kallweit, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Add support for fast link failure for lan8842, when this is enabled the PHY will detect link down immediately (~1ms). The disadvantage of this is that also small instability might be reported as link down. Therefore add this feature as a tunable configuration and the user will know when to enable or not. By default it is not enabled. Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com> --- v1->v2: - fix typo appaers->appears - simplify lan8842_set_fast_down as suggested by Russell --- drivers/net/phy/micrel.c | 79 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 77 insertions(+), 2 deletions(-)
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index e403cbbcead5b..5e3f41fceab21 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c@@ -107,6 +107,7 @@ #define LAN8814_INTC 0x18 #define LAN8814_INTS 0x1B +#define LAN8814_INT_FLF BIT(15) #define LAN8814_INT_LINK_DOWN BIT(2) #define LAN8814_INT_LINK_UP BIT(0) #define LAN8814_INT_LINK (LAN8814_INT_LINK_UP |\
@@ -2805,6 +2806,14 @@ static int ksz886x_cable_test_get_status(struct phy_device *phydev, return ret; } +/** + * LAN8814_PAGE_PCS - Selects Extended Page 0. + * + * This page appears to control the fast link failure and there are different + * debug info registers. + */ +#define LAN8814_PAGE_PCS 0 + /** * LAN8814_PAGE_AFE_PMA - Selects Extended Page 1. *
@@ -5910,7 +5919,8 @@ static int lan8842_config_intr(struct phy_device *phydev) if (err) return err; - err = phy_write(phydev, LAN8814_INTC, LAN8814_INT_LINK); + err = phy_write(phydev, LAN8814_INTC, + LAN8814_INT_LINK | LAN8814_INT_FLF); } else { err = phy_write(phydev, LAN8814_INTC, 0); if (err)
@@ -5986,7 +5996,7 @@ static irqreturn_t lan8842_handle_interrupt(struct phy_device *phydev) return IRQ_NONE; } - if (irq_status & LAN8814_INT_LINK) { + if (irq_status & (LAN8814_INT_LINK | LAN8814_INT_FLF)) { phy_trigger_machine(phydev); ret = IRQ_HANDLED; }
@@ -6055,6 +6065,69 @@ static int lan8842_update_stats(struct phy_device *phydev) return 0; } +#define LAN8842_FLF 15 /* 0x0e */ +#define LAN8842_FLF_ENA BIT(1) +#define LAN8842_FLF_ENA_LINK_DOWN BIT(0) + +static int lan8842_get_fast_down(struct phy_device *phydev, u8 *msecs) +{ + int ret; + + ret = lanphy_read_page_reg(phydev, LAN8814_PAGE_PCS, LAN8842_FLF); + if (ret < 0) + return ret; + + if (ret & LAN8842_FLF_ENA) + *msecs = ETHTOOL_PHY_FAST_LINK_DOWN_ON; + else + *msecs = ETHTOOL_PHY_FAST_LINK_DOWN_OFF; + + return 0; +} + +static int lan8842_set_fast_down(struct phy_device *phydev, const u8 *msecs) +{ + u16 flf; + + switch (*msecs) { + case ETHTOOL_PHY_FAST_LINK_DOWN_OFF: + flf = 0; + break; + case ETHTOOL_PHY_FAST_LINK_DOWN_ON: + flf = LAN8842_FLF_ENA | LAN8842_FLF_ENA_LINK_DOWN; + break; + default: + return -EINVAL; + } + + return lanphy_modify_page_reg(phydev, LAN8814_PAGE_PCS, + LAN8842_FLF, + LAN8842_FLF_ENA | + LAN8842_FLF_ENA_LINK_DOWN, flf); +} + +static int lan8842_get_tunable(struct phy_device *phydev, + struct ethtool_tunable *tuna, void *data) +{ + switch (tuna->id) { + case ETHTOOL_PHY_FAST_LINK_DOWN: + return lan8842_get_fast_down(phydev, data); + default: + return -EOPNOTSUPP; + } +} + +static int lan8842_set_tunable(struct phy_device *phydev, + struct ethtool_tunable *tuna, const void *data) +{ + switch (tuna->id) { + case ETHTOOL_PHY_FAST_LINK_DOWN: + return lan8842_set_fast_down(phydev, data); + default: + return -EOPNOTSUPP; + } +} + static void lan8842_get_phy_stats(struct phy_device *phydev, struct ethtool_eth_phy_stats *eth_stats, struct ethtool_phy_stats *stats)
@@ -6299,6 +6372,8 @@ static struct phy_driver ksphy_driver[] = { .handle_interrupt = lan8842_handle_interrupt, .get_phy_stats = lan8842_get_phy_stats, .update_stats = lan8842_update_stats, + .get_tunable = lan8842_get_tunable, + .set_tunable = lan8842_set_tunable, .cable_test_start = lan8814_cable_test_start, .cable_test_get_status = ksz886x_cable_test_get_status, }, {
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2.34.1