From: Francesco Dolcini <francesco.dolcini@toradex.com>
To: Andrew Lunn <andrew@lunn.ch>,
Heiner Kallweit <hkallweit1@gmail.com>,
Russell King <linux@armlinux.org.uk>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>
Cc: philippe.schenker@toradex.com,
Francesco Dolcini <francesco.dolcini@toradex.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] net: phy: micrel: ksz9131 led errata workaround
Date: Wed, 6 Oct 2021 09:37:55 +0200 [thread overview]
Message-ID: <20211006073755.429469-1-francesco.dolcini@toradex.com> (raw)
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
(http://ww1.microchip.com/downloads/en/DeviceDoc/80000863A.pdf) and
according to that it will not be corrected in a future silicon revision.
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
---
drivers/net/phy/micrel.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index c330a5a9f665..661dedec84c4 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -1003,6 +1003,23 @@ 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 ret = 0;
+
+ if (phy_read_mmd(phydev, 2, 0) & BIT(4))
+ ret = phy_set_bits(phydev, 0x1e, BIT(9));
+
+ return ret;
+}
+
static int ksz9131_config_init(struct phy_device *phydev)
{
struct device_node *of_node;
@@ -1058,6 +1075,10 @@ 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
next reply other threads:[~2021-10-06 7:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-06 7:37 Francesco Dolcini [this message]
2021-10-06 9:39 ` [PATCH] net: phy: micrel: ksz9131 led errata workaround Francesco Dolcini
2021-10-06 21:57 ` Andrew Lunn
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