net: phy: dp83867: Set FORCE_LINK_GOOD to default after reset

BugLink: https://bugs.launchpad.net/bugs/1862429
[ Upstream commit 86ffe920e669ec73035e84553e18edf17d16317c ]

According to the Datasheet this bit should be 0 (Normal operation) in
default. With the FORCE_LINK_GOOD bit set, it is not possible to get a
link. This patch sets FORCE_LINK_GOOD to the default value after
resetting the phy.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index 9a4b5a64992bc7f1a4881cb68bba927e43347248..8dfcf62ee8073baad19de53009a6513983fd2ff9 100644 (file)
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -76,6 +76,7 @@
 #define DP83867_PHYCR_FIFO_DEPTH_MAX           0x03
 #define DP83867_PHYCR_FIFO_DEPTH_MASK          GENMASK(15, 14)
 #define DP83867_PHYCR_RESERVED_MASK            BIT(11)
+#define DP83867_PHYCR_FORCE_LINK_GOOD          BIT(10)
 
 /* RGMIIDCTL bits */
 #define DP83867_RGMII_TX_CLK_DELAY_MAX         0xf
@@ -435,7 +436,12 @@ static int dp83867_phy_reset(struct phy_device *phydev)
 
        usleep_range(10, 20);
 
-       return 0;
+       /* After reset FORCE_LINK_GOOD bit is set. Although the
+        * default value should be unset. Disable FORCE_LINK_GOOD
+        * for the phy to work properly.
+        */
+       return phy_modify(phydev, MII_DP83867_PHYCTRL,
+                        DP83867_PHYCR_FORCE_LINK_GOOD, 0);
 }
 
 static struct phy_driver dp83867_driver[] = {