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From: Horatiu Vultur <horatiu.vultur@microchip.com>
To: <andrew@lunn.ch>, <hkallweit1@gmail.com>, <linux@armlinux.org.uk>,
	<davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
	<pabeni@redhat.com>, <wojciech.drewek@intel.com>,
	<arun.ramadoss@microchip.com>
CC: <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<UNGLinuxDriver@microchip.com>, Horatiu Vultur <horatiu.vultur@microchip.com>
Subject: [PATCH net-next v3 1/2] net: phy: micrel: lan8814 led errata
Date: Mon, 4 Mar 2024 10:15:47 +0100
Message-ID: <20240304091548.1386022-2-horatiu.vultur@microchip.com>
In-Reply-To: <20240304091548.1386022-1-horatiu.vultur@microchip.com>
References: <20240304091548.1386022-1-horatiu.vultur@microchip.com>
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Lan8814 phy led behavior is not correct. It was noticed that the led
still remains ON when the cable is unplugged while there was traffic
passing at that time.

The fix consists in clearing bit 10 of register 0x38, in this way the
led behaviour is correct and gets OFF when there is no link.

Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 drivers/net/phy/micrel.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 9b69735819896..88cc03982bb78 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -114,6 +114,9 @@
 #define LAN8814_INTR_CTRL_REG_POLARITY		BIT(1)
 #define LAN8814_INTR_CTRL_REG_INTR_ENABLE	BIT(0)
 
+#define LAN8814_EEE_STATE			0x38
+#define LAN8814_EEE_STATE_MASK2P5P		BIT(10)
+
 /* Represents 1ppm adjustment in 2^32 format with
  * each nsec contains 4 clock cycles.
  * The value is calculated as following: (1/1000000)/((2^-32)/4)
@@ -3288,6 +3291,19 @@ static int lan8814_release_coma_mode(struct phy_device *phydev)
 	return 0;
 }
 
+static void lan8814_clear_2psp_bit(struct phy_device *phydev)
+{
+	u16 val;
+
+	/* It was noticed that when traffic is passing through the PHY and the
+	 * cable is removed then the LED was still one even though there is no
+	 * link
+	 */
+	val = lanphy_read_page_reg(phydev, 2, LAN8814_EEE_STATE);
+	val &= ~LAN8814_EEE_STATE_MASK2P5P;
+	lanphy_write_page_reg(phydev, 2, LAN8814_EEE_STATE, val);
+}
+
 static int lan8814_probe(struct phy_device *phydev)
 {
 	const struct kszphy_type *type = phydev->drv->driver_data;
@@ -3324,6 +3340,9 @@ static int lan8814_probe(struct phy_device *phydev)
 
 	lan8814_ptp_init(phydev);
 
+	/* Errata workarounds */
+	lan8814_clear_2psp_bit(phydev);
+
 	return 0;
 }
 
-- 
2.34.1