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authorRussell King <rmk+kernel@armlinux.org.uk>2021-01-12 22:59:43 +0000
committerJakub Kicinski <kuba@kernel.org>2021-01-14 15:36:32 -0800
commit3c51fa5d2afe7a4909b53af5019635326389dd29 (patch)
tree1aea27a33e80e6e8e54b8fe63be9aee6afe5eab7 /drivers/net/phy
parent0ae5b43d6dde6003070106e97cd0d41bace2eeb2 (diff)
net: phy: ar803x: disable extended next page bit
This bit is enabled by default and advertises support for extended next page support. XNP is only needed for 10GBase-T and MultiGig support which is not supported. Additionally, Cisco MultiGig switches will read this bit and attempt 10Gb negotiation even though Next Page support is disabled. This will cause timeouts when the interface is forced to 100Mbps and auto-negotiation will fail. The interfaces are only 1000Base-T and supporting auto-negotiation for this only requires the Next Page bit to be set. Taken from: https://github.com/SolidRun/linux-stable/commit/7406c5244b7ea6bc17a2afe8568277a8c4b126a9 and adapted to mainline kernels by rmk. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/E1kzSdb-000417-FJ@rmk-PC.armlinux.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/phy')
-rw-r--r--drivers/net/phy/at803x.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 9636edb8d618..c8d276d96798 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -587,7 +587,13 @@ static int at803x_config_init(struct phy_device *phydev)
return ret;
}
- return 0;
+ /* Ar803x extended next page bit is enabled by default. Cisco
+ * multigig switches read this bit and attempt to negotiate 10Gbps
+ * rates even if the next page bit is disabled. This is incorrect
+ * behaviour but we still need to accommodate it. XNP is only needed
+ * for 10Gbps support, so disable XNP.
+ */
+ return phy_modify(phydev, MII_ADVERTISE, MDIO_AN_CTRL1_XNP, 0);
}
static int at803x_ack_interrupt(struct phy_device *phydev)