net: dsa: mv88e6xxx: wait after reset deactivation

[ Upstream commit 7b75e49de424ceb53d13e60f35d0a73765626fda ]

Add a 1ms delay after reset deactivation. Otherwise the chip returns
bogus ID value. This is observed with 88E6390 (Peridot) chip.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
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>

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index ae750ab9a4d7f5cacb3bd877b7c733db66c99b8a..5f81d9a3a2a69fd9cd1de8233d4b5347daff3d95 100644 (file)
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -4910,6 +4910,8 @@ static int mv88e6xxx_probe(struct mdio_device *mdiodev)
                err = PTR_ERR(chip->reset);
                goto out;
        }
+       if (chip->reset)
+               usleep_range(1000, 2000);
 
        err = mv88e6xxx_detect(chip);
        if (err)