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From:   Luo Jie <luoj@codeaurora.org>
To:     andrew@lunn.ch, hkallweit1@gmail.com, linux@armlinux.org.uk,
        davem@davemloft.net, kuba@kernel.org
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        sricharan@codeaurora.org, Luo Jie <luoj@codeaurora.org>
Subject: [PATCH v6 13/14] net: phy: adjust qca8081 master/slave seed value if link down
Date:   Sat, 23 Oct 2021 17:54:52 +0800
Message-Id: <20211023095453.22615-14-luoj@codeaurora.org>
In-Reply-To: <20211023095453.22615-1-luoj@codeaurora.org>
References: <20211023095453.22615-1-luoj@codeaurora.org>
Precedence: bulk

1. The master/slave seed needs to be updated when the link can't
be created.

2. The case where two qca8081 PHYs are connected each other and
master/slave seed is generated as the same value also needs
to be considered, so adding this code change into read_status
instead of link_change_notify.

Signed-off-by: Luo Jie <luoj@codeaurora.org>
---
 drivers/net/phy/at803x.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 1418db4f2091..00733badcda5 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -1655,6 +1655,22 @@ static int qca808x_read_status(struct phy_device *phydev)
 	else
 		phydev->interface = PHY_INTERFACE_MODE_SMII;
 
+	/* generate seed as a lower random value to make PHY linked as SLAVE easily,
+	 * except for master/slave configuration fault detected.
+	 * the reason for not putting this code into the function link_change_notify is
+	 * the corner case where the link partner is also the qca8081 PHY and the seed
+	 * value is configured as the same value, the link can't be up and no link change
+	 * occurs.
+	 */
+	if (!phydev->link) {
+		if (phydev->master_slave_state == MASTER_SLAVE_STATE_ERR) {
+			qca808x_phy_ms_seed_enable(phydev, false);
+		} else {
+			qca808x_phy_ms_random_seed_set(phydev);
+			qca808x_phy_ms_seed_enable(phydev, true);
+		}
+	}
+
 	return 0;
 }
 
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