Messages in this thread Patch in this message | | | From | Francesco Dolcini <> | Subject | [PATCH net-next v2] net: phy: micrel: ksz9131 led errata workaround | Date | Thu, 7 Oct 2021 18:45:35 +0200 |
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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
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com> --- Changes v1 => v2: 1. corrected errata URL in commit message 2. check phy_read_mmd return value --- drivers/net/phy/micrel.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c index c330a5a9f665..b70f62efdbc3 100644 --- a/drivers/net/phy/micrel.c +++ b/drivers/net/phy/micrel.c @@ -1003,6 +1003,26 @@ static int ksz9131_config_rgmii_delay(struct phy_device *phydev) txcdll_val); } +/* 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, 2, 0); + if (reg < 0) + return reg; + + if (!(reg & BIT(4))) + return 0; + + return phy_set_bits(phydev, 0x1e, BIT(9)); +} + static int ksz9131_config_init(struct phy_device *phydev) { struct device_node *of_node; @@ -1058,6 +1078,10 @@ static int ksz9131_config_init(struct phy_device *phydev) if (ret < 0) return ret; + ret = ksz9131_led_errata(phydev); + if (ret < 0) + return ret; + return 0; } -- 2.25.1
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