Micrel KSZ9131 PHY LED behavior is not correct when configured in Individual Mode, LED1 (Activity LED) is in the ON state when there is no-link.
Workaround this by setting bit 9 of register 0x1e after verifying that the LED configuration is Individual Mode. This issue is described in KSZ9131RNX Silicon Errata DS80000693B [*] and according to that it will not be corrected in a future silicon revision. [*] https://ww1.microchip.com/downloads/en/DeviceDoc/KSZ9131RNX-Silicon-Errata-and-Data-Sheet-Clarification-80000863B.pdf Based on commit 0316c7e66bbd in the Linux kernel. Signed-off-by: Paul Barker <paul.barker...@bp.renesas.com> --- drivers/net/phy/micrel_ksz90x1.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/net/phy/micrel_ksz90x1.c b/drivers/net/phy/micrel_ksz90x1.c index c48ae6e88f30..4f99b115a3c7 100644 --- a/drivers/net/phy/micrel_ksz90x1.c +++ b/drivers/net/phy/micrel_ksz90x1.c @@ -436,6 +436,26 @@ static int ksz9131_config_rgmii_delay(struct phy_device *phydev) return ret; } +/* Silicon Errata DS80000693B + * + * When LEDs are configured in Individual Mode, LED1 is ON in a no-link + * condition. Workaround is to set register 0x1e, bit 9, this way LED1 behaves + * according to the datasheet (off if there is no link). + */ +static int ksz9131_led_errata(struct phy_device *phydev) +{ + int reg; + + reg = phy_read_mmd(phydev, KSZ9131RN_MMD_COMMON_CTRL_REG, 0); + if (reg < 0) + return reg; + + if (!(reg & BIT(4))) + return 0; + + return phy_set_bits(phydev, MDIO_DEVAD_NONE, 0x1e, BIT(9)); +} + static int ksz9131_config(struct phy_device *phydev) { int ret; @@ -446,6 +466,10 @@ static int ksz9131_config(struct phy_device *phydev) return ret; } + ret = ksz9131_led_errata(phydev); + if (ret < 0) + return ret; + /* add an option to disable the gigabit feature of this PHY */ if (env_get("disable_giga")) { unsigned features; -- 2.43.0
