ar71xx: allow to override at803x sgmii aneg status

When checking the outcome of the PHY autonegotiation status, at803x
currently returns false in case the SGMII side is not established.

Due to a hardware-bug, ag71xx needs to fixup the SoCs SGMII side, which
it can't as it is not aware of the link-establishment.

This commit allows to ignore the SGMII side autonegotiation status to
allow ag71xx to do the fixup work.

Signed-off-by: David Bauer <mail@david-bauer.net>

target/linux/ar71xx/files/arch/mips/ath79/mach-fritz450e.c

@@ -122,6 +122,7 @@ static struct gpio_keys_button fritz450E_gpio_keys[] __initdata = {
 static struct at803x_platform_data fritz450E_at803x_data = {
 	.disable_smarteee = 1,
 	.has_reset_gpio = 1,
+	.override_sgmii_aneg = 1,
 	.reset_gpio = FRITZ450E_GPIO_PHY_RESET,
 };
 

target/linux/ar71xx/patches-4.9/903-at803x-add-sgmii-aneg-override-pdata.patch

@@ -0,0 +1,42 @@
+Index: linux-4.9.111/drivers/net/phy/at803x.c
+===================================================================
+--- linux-4.9.111.orig/drivers/net/phy/at803x.c
++++ linux-4.9.111/drivers/net/phy/at803x.c
+@@ -461,12 +461,15 @@ static void at803x_link_change_notify(st
+ 
+ static int at803x_aneg_done(struct phy_device *phydev)
+ {
++	struct at803x_platform_data *pdata;
+ 	int ccr;
+ 
+ 	int aneg_done = genphy_aneg_done(phydev);
+ 	if (aneg_done != BMSR_ANEGCOMPLETE)
+ 		return aneg_done;
+ 
++	pdata = dev_get_platdata(&phydev->mdio.dev);
++
+ 	/*
+ 	 * in SGMII mode, if copper side autoneg is successful,
+ 	 * also check SGMII side autoneg result
+@@ -481,7 +484,8 @@ static int at803x_aneg_done(struct phy_d
+ 	/* check if the SGMII link is OK. */
+ 	if (!(phy_read(phydev, AT803X_PSSR) & AT803X_PSSR_MR_AN_COMPLETE)) {
+ 		pr_warn("803x_aneg_done: SGMII link is not ok\n");
+-		aneg_done = 0;
++		if (!pdata || !pdata->override_sgmii_aneg)
++			aneg_done = 0;
+ 	}
+ 	/* switch back to copper page */
+ 	phy_write(phydev, AT803X_REG_CHIP_CONFIG, ccr | AT803X_BT_BX_REG_SEL);
+Index: linux-4.9.111/include/linux/platform_data/phy-at803x.h
+===================================================================
+--- linux-4.9.111.orig/include/linux/platform_data/phy-at803x.h
++++ linux-4.9.111/include/linux/platform_data/phy-at803x.h
+@@ -7,6 +7,7 @@ struct at803x_platform_data {
+ 	int enable_rgmii_rx_delay:1;
+ 	int fixup_rgmii_tx_delay:1;
+ 	int has_reset_gpio:1;
++	int override_sgmii_aneg:1;
+ 	int reset_gpio;
+ };
+