net: phy: bcm7xxx: update workaround to fix 100BaseT corner cases

Update the AFE_TX_CONFIG value to solve marginal rise/fall issues
observed when the link is operating in 100BaseT. This workaround applies
to GPHY revisions D0, E0 and newer.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/bcm7xxx.c

@@ -136,8 +136,8 @@ static int bcm7xxx_28nm_d0_afe_config_init(struct phy_device *phydev)
 	/* AFE_RX_LP_COUNTER, set RX bandwidth to maximum */
 	phy_write_misc(phydev, AFE_RX_LP_COUNTER, 0x7fc0);
 
-	/* AFE_TX_CONFIG, set 1000BT Cfeed=110 for all ports */
-	phy_write_misc(phydev, AFE_TX_CONFIG, 0x0061);
+	/* AFE_TX_CONFIG, set 100BT Cfeed=011 to improve rise/fall time */
+	phy_write_misc(phydev, AFE_TX_CONFIG, 0x431);
 
 	/* AFE_VDCA_ICTRL_0, set Iq=1101 instead of 0111 for AB symmetry */
 	phy_write_misc(phydev, AFE_VDCA_ICTRL_0, 0xa7da);
@@ -167,6 +167,9 @@ static int bcm7xxx_28nm_e0_plus_afe_config_init(struct phy_device *phydev)
 	/* AFE_RXCONFIG_1, provide more margin for INL/DNL measurement */
 	phy_write_misc(phydev, AFE_RXCONFIG_1, 0x9b2f);
 
+	/* AFE_TX_CONFIG, set 100BT Cfeed=011 to improve rise/fall time */
+	phy_write_misc(phydev, AFE_TX_CONFIG, 0x431);
+
 	/* AFE_VDCA_ICTRL_0, set Iq=1101 instead of 0111 for AB symmetry */
 	phy_write_misc(phydev, AFE_VDCA_ICTRL_0, 0xa7da);