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From:   Hans Andersson <haan@cellavision.se>
To:     <andrew@lunn.ch>
CC:     <f.fainelli@gmail.com>, <hkallweit1@gmail.com>,
        <davem@davemloft.net>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <antoine.tenart@bootlin.com>,
        Hans Andersson <hans.andersson@cellavision.se>
Subject: [PATCH] net: phy: micrel: add Asym Pause workaround for KSZ9021
Date:   Thu, 26 Sep 2019 09:54:37 +0200
Message-ID: <20190926075437.18088-1-haan@cellavision.se>
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From: Hans Andersson <hans.andersson@cellavision.se>

The Micrel KSZ9031 PHY may fail to establish a link when the Asymmetric
Pause capability is set. This issue is described in a Silicon Errata
(DS80000691D or DS80000692D), which advises to always disable the
capability.

Micrel KSZ9021 has no errata, but has the same issue with Asymmetric Pause.
This patch apply the same workaround as the one for KSZ9031.

Signed-off-by: Hans Andersson <hans.andersson@cellavision.se>
---
 drivers/net/phy/micrel.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 3c8186f..2fea554 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -763,6 +763,8 @@ static int ksz9031_get_features(struct phy_device *phydev)
 	 * Whenever the device's Asymmetric Pause capability is set to 1,
 	 * link-up may fail after a link-up to link-down transition.
 	 *
+	 * The Errata Sheet is for ksz9031, but ksz9021 has the same issue
+	 *
 	 * Workaround:
 	 * Do not enable the Asymmetric Pause capability bit.
 	 */
@@ -1076,6 +1078,7 @@ static struct phy_driver ksphy_driver[] = {
 	/* PHY_GBIT_FEATURES */
 	.driver_data	= &ksz9021_type,
 	.probe		= kszphy_probe,
+	.get_features	= ksz9031_get_features,
 	.config_init	= ksz9021_config_init,
 	.ack_interrupt	= kszphy_ack_interrupt,
 	.config_intr	= kszphy_config_intr,
-- 
2.17.1