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From: Siddharth Vadapalli <s-vadapalli@ti.com>
To: <andrew@lunn.ch>, <hkallweit1@gmail.com>, <linux@armlinux.org.uk>,
	<davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
	<pabeni@redhat.com>
Cc: <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>, <srk@ti.com>,
	<s-vadapalli@ti.com>
Subject: [RFC PATCH 1/2] net: phy: dp83867: add w/a for packet errors seen with short cables
Date: Tue, 25 Apr 2023 11:14:28 +0530	[thread overview]
Message-ID: <20230425054429.3956535-2-s-vadapalli@ti.com> (raw)
In-Reply-To: <20230425054429.3956535-1-s-vadapalli@ti.com>

From: Grygorii Strashko <grygorii.strashko@ti.com>

Introduce the W/A for packet errors seen with short cables (<1m) between
two DP83867 PHYs.

The W/A recommended by DM requires FFE Equalizer Configuration tuning by
writing value 0x0E81 to DSP_FFE_CFG register (0x012C), surrounded by hard
and soft resets as follows:

write_reg(0x001F, 0x8000); //hard reset
write_reg(DSP_FFE_CFG, 0x0E81);
write_reg(0x001F, 0x4000); //soft reset

Since  DP83867 PHY DM says "Changing this register to 0x0E81, will not
affect Long Cable performance.", enable the W/A by default.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
---
 drivers/net/phy/dp83867.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index 5821f04c69dc..ba60cf35872e 100644
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -42,6 +42,7 @@
 #define DP83867_STRAP_STS1	0x006E
 #define DP83867_STRAP_STS2	0x006f
 #define DP83867_RGMIIDCTL	0x0086
+#define DP83867_DSP_FFE_CFG	0X012C
 #define DP83867_RXFCFG		0x0134
 #define DP83867_RXFPMD1	0x0136
 #define DP83867_RXFPMD2	0x0137
@@ -934,8 +935,20 @@ static int dp83867_phy_reset(struct phy_device *phydev)
 
 	usleep_range(10, 20);
 
-	return phy_modify(phydev, MII_DP83867_PHYCTRL,
+	err = phy_modify(phydev, MII_DP83867_PHYCTRL,
 			 DP83867_PHYCR_FORCE_LINK_GOOD, 0);
+	if (err < 0)
+		return err;
+
+	phy_write_mmd(phydev, DP83867_DEVADDR, DP83867_DSP_FFE_CFG, 0X0E81);
+
+	err = phy_write(phydev, DP83867_CTRL, DP83867_SW_RESTART);
+	if (err < 0)
+		return err;
+
+	usleep_range(10, 20);
+
+	return 0;
 }
 
 static void dp83867_link_change_notify(struct phy_device *phydev)
-- 
2.25.1


WARNING: multiple messages have this Message-ID (diff)
From: Siddharth Vadapalli <s-vadapalli@ti.com>
To: <andrew@lunn.ch>, <hkallweit1@gmail.com>, <linux@armlinux.org.uk>,
	<davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
	<pabeni@redhat.com>
Cc: <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>, <srk@ti.com>,
	<s-vadapalli@ti.com>
Subject: [RFC PATCH 1/2] net: phy: dp83867: add w/a for packet errors seen with short cables
Date: Tue, 25 Apr 2023 11:14:28 +0530	[thread overview]
Message-ID: <20230425054429.3956535-2-s-vadapalli@ti.com> (raw)
In-Reply-To: <20230425054429.3956535-1-s-vadapalli@ti.com>

From: Grygorii Strashko <grygorii.strashko@ti.com>

Introduce the W/A for packet errors seen with short cables (<1m) between
two DP83867 PHYs.

The W/A recommended by DM requires FFE Equalizer Configuration tuning by
writing value 0x0E81 to DSP_FFE_CFG register (0x012C), surrounded by hard
and soft resets as follows:

write_reg(0x001F, 0x8000); //hard reset
write_reg(DSP_FFE_CFG, 0x0E81);
write_reg(0x001F, 0x4000); //soft reset

Since  DP83867 PHY DM says "Changing this register to 0x0E81, will not
affect Long Cable performance.", enable the W/A by default.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
---
 drivers/net/phy/dp83867.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index 5821f04c69dc..ba60cf35872e 100644
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -42,6 +42,7 @@
 #define DP83867_STRAP_STS1	0x006E
 #define DP83867_STRAP_STS2	0x006f
 #define DP83867_RGMIIDCTL	0x0086
+#define DP83867_DSP_FFE_CFG	0X012C
 #define DP83867_RXFCFG		0x0134
 #define DP83867_RXFPMD1	0x0136
 #define DP83867_RXFPMD2	0x0137
@@ -934,8 +935,20 @@ static int dp83867_phy_reset(struct phy_device *phydev)
 
 	usleep_range(10, 20);
 
-	return phy_modify(phydev, MII_DP83867_PHYCTRL,
+	err = phy_modify(phydev, MII_DP83867_PHYCTRL,
 			 DP83867_PHYCR_FORCE_LINK_GOOD, 0);
+	if (err < 0)
+		return err;
+
+	phy_write_mmd(phydev, DP83867_DEVADDR, DP83867_DSP_FFE_CFG, 0X0E81);
+
+	err = phy_write(phydev, DP83867_CTRL, DP83867_SW_RESTART);
+	if (err < 0)
+		return err;
+
+	usleep_range(10, 20);
+
+	return 0;
 }
 
 static void dp83867_link_change_notify(struct phy_device *phydev)
-- 
2.25.1


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  reply	other threads:[~2023-04-25  5:45 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-25  5:44 [RFC PATCH 0/2] DP83867/DP83869 Ethernet PHY workaround/fix Siddharth Vadapalli
2023-04-25  5:44 ` Siddharth Vadapalli
2023-04-25  5:44 ` Siddharth Vadapalli [this message]
2023-04-25  5:44   ` [RFC PATCH 1/2] net: phy: dp83867: add w/a for packet errors seen with short cables Siddharth Vadapalli
2023-04-25 12:05   ` Andrew Lunn
2023-04-25 12:05     ` Andrew Lunn
2023-04-26  5:09     ` Siddharth Vadapalli
2023-04-26  5:09       ` Siddharth Vadapalli
2023-04-26 12:36       ` Andrew Lunn
2023-04-26 12:36         ` Andrew Lunn
2023-04-27  4:02         ` Siddharth Vadapalli
2023-04-27  4:02           ` Siddharth Vadapalli
2023-04-25  5:44 ` [RFC PATCH 2/2] net: phy: dp83869: fix mii mode when rgmii strap cfg is used Siddharth Vadapalli
2023-04-25  5:44   ` Siddharth Vadapalli
2023-04-25 12:18   ` Andrew Lunn
2023-04-25 12:18     ` Andrew Lunn
2023-04-26  5:49     ` Siddharth Vadapalli
2023-04-26  5:49       ` Siddharth Vadapalli
2023-04-26 12:41       ` Andrew Lunn
2023-04-26 12:41         ` Andrew Lunn
2023-04-27  4:08         ` Siddharth Vadapalli
2023-04-27  4:08           ` Siddharth Vadapalli
2023-04-27 12:04           ` Andrew Lunn
2023-04-27 12:04             ` Andrew Lunn

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