[PATCH 4.0 20/55] net: phy: fix phy link up when limiting speed via device tree

Greg Kroah-Hartman
2015-07-08T08:16:01Z

From: Mugunthan V N <mugunthanvnm@ti.com>

[ Upstream commit eb686231fce3770299760f24fdcf5ad041f44153 ]

When limiting phy link speed using "max-speed" to 100mbps or less on a
giga bit phy, phy never completes auto negotiation and phy state
machine is held in PHY_AN. Fixing this issue by comparing the giga
bit advertise though phydev->supported doesn't have it but phy has
BMSR_ESTATEN set. So that auto negotiation is restarted as old and
new advertise are different and link comes up fine.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/phy/phy_device.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -796,10 +796,11 @@ static int genphy_config_advert(struct p
if (phydev->supported & (SUPPORTED_1000baseT_Half |
SUPPORTED_1000baseT_Full)) {
adv |= ethtool_adv_to_mii_ctrl1000_t(advertise);
- if (adv != oldadv)
- changed = 1;
}

+ if (adv != oldadv)
+ changed = 1;
+
err = phy_write(phydev, MII_CTRL1000, adv);
if (err < 0)
return err;