From 9be73bb093813473a80b4d14b01cdf5de76991f1 Mon Sep 17 00:00:00 2001
From: Kevin Hao <haokexin@gmail.com>
Date: Tue, 20 Mar 2018 09:44:53 +0800
Subject: [PATCH 1/2] net: phy: realtek: Use the dummy stubs for MMD register
 access for rtl8211b
Git-commit: 0231b1a074c672f8c00da00a57144072890d816b
Patch-mainline: v4.16-rc7
References: git-fixes

The Ethernet on mpc8315erdb is broken since commit b6b5e8a69118
("gianfar: Disable EEE autoneg by default"). The reason is that
even though the rtl8211b doesn't support the MMD extended registers
access, it does return some random values if we trying to access
the MMD register via indirect method. This makes it seem that the
EEE is supported by this phy device. And the subsequent writing to
the MMD registers does cause the phy malfunction. So use the dummy
stubs for the MMD register access to fix this issue.

Fixes: b6b5e8a69118 ("gianfar: Disable EEE autoneg by default")
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
 drivers/net/phy/realtek.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index e221feb58d9f..f75c94daf3c2 100644
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -177,6 +177,8 @@ static struct phy_driver realtek_drvs[] = {
 		.flags		= PHY_HAS_INTERRUPT,
 		.ack_interrupt	= &rtl821x_ack_interrupt,
 		.config_intr	= &rtl8211b_config_intr,
+		.read_mmd	= &genphy_read_mmd_unsupported,
+		.write_mmd	= &genphy_write_mmd_unsupported,
 	}, {
 		.phy_id		= 0x001cc914,
 		.name		= "RTL8211DN Gigabit Ethernet",
-- 
2.16.4