[PATCH 4.9 135/223] net: dsa: mv88e6xxx: wait after reset deactivation

[Greg Kroah-Hartman]

From: Baruch Siach <baruch@xxxxxxxxxx>

[ 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@xxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/dsa/mv88e6xxx/chip.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -3846,6 +3846,8 @@ static int mv88e6xxx_probe(struct mdio_d
 		mv88e6xxx_mdio_unregister(chip);
 		return err;
 	}
+	if (chip->reset)
+		usleep_range(1000, 2000);
 
 	return 0;
 }