diff options
| author | Florian Fainelli <f.fainelli@gmail.com> | 2015-06-26 10:39:04 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-06-28 20:28:20 -0700 |
| commit | 8e346e1594bab6c06b6b4d2938c881729b03041d (patch) | |
| tree | 87180c84eaafd9ee5dc56c021a3a3d72d0408f00 /drivers | |
| parent | 8031612d7fa8e49589a91da238a93a067826c668 (diff) | |
| download | linux-8e346e1594bab6c06b6b4d2938c881729b03041d.tar.bz2 | |
net: phy: bcm7xxx: workaround MDIO management controller initial read
The initial MDIO read or write towards the BCM7xxx integrated PHY may
fail, workaround this by inserting a dummy MII_BMSR read to force the
MDIO management controller to see at least one valid transaction and get
out of stuck state out of reset.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/phy/bcm7xxx.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/net/phy/bcm7xxx.c b/drivers/net/phy/bcm7xxx.c index 4dea85bfc545..6b701b3ded74 100644 --- a/drivers/net/phy/bcm7xxx.c +++ b/drivers/net/phy/bcm7xxx.c @@ -246,6 +246,13 @@ static int bcm7xxx_28nm_config_init(struct phy_device *phydev) pr_info_once("%s: %s PHY revision: 0x%02x, patch: %d\n", dev_name(&phydev->dev), phydev->drv->name, rev, patch); + /* Dummy read to a register to workaround an issue upon reset where the + * internal inverter may not allow the first MDIO transaction to pass + * the MDIO management controller and make us return 0xffff for such + * reads. + */ + phy_read(phydev, MII_BMSR); + switch (rev) { case 0xb0: ret = bcm7xxx_28nm_b0_afe_config_init(phydev); |