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-a...
Based on commit 0316c7e66bbd in the Linux kernel.
Signed-off-by: Paul Barker paul.barker.ct@bp.renesas.com --- Changes v1->v2: - Split out of series adding RZ/G2L Ethernet support [1] - Add symbols KSZ9131RN_COMMON_CTRL, KSZ9131RN_COMMON_CTRL_LED_MODE, KSZ9131RN_LED_ERRATA_REG, KSZ9131RN_LED_ERRATA_BITS
[1]: https://lore.kernel.org/all/20241024152448.102-1-paul.barker.ct@bp.renesas.c...
drivers/net/phy/micrel_ksz90x1.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/drivers/net/phy/micrel_ksz90x1.c b/drivers/net/phy/micrel_ksz90x1.c index c48ae6e88f30..b33457910795 100644 --- a/drivers/net/phy/micrel_ksz90x1.c +++ b/drivers/net/phy/micrel_ksz90x1.c @@ -389,6 +389,12 @@ U_BOOT_PHY_DRIVER(ksz9031) = { #define KSZ9131RN_DLL_ENABLE_DELAY 0 #define KSZ9131RN_DLL_DISABLE_DELAY BIT(12)
+#define KSZ9131RN_COMMON_CTRL 0 +#define KSZ9131RN_COMMON_CTRL_LED_MODE BIT(4) + +#define KSZ9131RN_LED_ERRATA_REG 0x1e +#define KSZ9131RN_LED_ERRATA_BITS BIT(9) + static int ksz9131_config_rgmii_delay(struct phy_device *phydev) { struct phy_driver *drv = phydev->drv; @@ -436,6 +442,28 @@ 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, + KSZ9131RN_COMMON_CTRL); + if (reg < 0) + return reg; + + if (!(reg & KSZ9131RN_COMMON_CTRL_LED_MODE)) + return 0; + + return phy_set_bits(phydev, MDIO_DEVAD_NONE, KSZ9131RN_LED_ERRATA_REG, + KSZ9131RN_LED_ERRATA_BITS); +} + static int ksz9131_config(struct phy_device *phydev) { int ret; @@ -446,6 +474,10 @@ 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;