From bb928fbe0f05d98570f6d10b5ab2961323ed1f89 Mon Sep 17 00:00:00 2001 From: Esben Haabendal Date: Sun, 8 Apr 2018 22:17:01 +0200 Subject: dp83640: Ensure against premature access to PHY registers after reset [ Upstream commit 76327a35caabd1a932e83d6a42b967aa08584e5d ] The datasheet specifies a 3uS pause after performing a software reset. The default implementation of genphy_soft_reset() does not provide this, so implement soft_reset with the needed pause. Signed-off-by: Esben Haabendal Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/phy/dp83640.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/net/phy/dp83640.c b/drivers/net/phy/dp83640.c index b88f7d65953d..482ea404a2d4 100644 --- a/drivers/net/phy/dp83640.c +++ b/drivers/net/phy/dp83640.c @@ -1205,6 +1205,23 @@ static void dp83640_remove(struct phy_device *phydev) kfree(dp83640); } +static int dp83640_soft_reset(struct phy_device *phydev) +{ + int ret; + + ret = genphy_soft_reset(phydev); + if (ret < 0) + return ret; + + /* From DP83640 datasheet: "Software driver code must wait 3 us + * following a software reset before allowing further serial MII + * operations with the DP83640." + */ + udelay(10); /* Taking udelay inaccuracy into account */ + + return 0; +} + static int dp83640_config_init(struct phy_device *phydev) { struct dp83640_private *dp83640 = phydev->priv; @@ -1498,6 +1515,7 @@ static struct phy_driver dp83640_driver = { .flags = PHY_HAS_INTERRUPT, .probe = dp83640_probe, .remove = dp83640_remove, + .soft_reset = dp83640_soft_reset, .config_init = dp83640_config_init, .config_aneg = genphy_config_aneg, .read_status = genphy_read_status, -- cgit v1.2.3