From: Kevin Hao <haokexin@xxxxxxxxx> [ Upstream commit 0231b1a074c672f8c00da00a57144072890d816b ] 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@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 9cbe645e3d89..7d38af5ed4b5 100644 --- a/drivers/net/phy/realtek.c +++ b/drivers/net/phy/realtek.c @@ -138,6 +138,8 @@ static struct phy_driver realtek_drvs[] = { .read_status = &genphy_read_status, .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", -- 2.17.1