net: dsa: mv88e6060: fix switch MAC address

The 88E6060 Ethernet switch always transmits the multicast bit of the
switch MAC address as a zero. It re-uses the corresponding bit 8 of the
register "Switch MAC Address Register Bytes 0 & 1" for "DiffAddr".

If the "DiffAddr" bit is 0, then all ports transmit the same source
address. If it is set to 1, then bit 2:0 are used for the port number.

The mv88e6060 driver is currently wrongly shifting the MAC address byte
0 by 9. To fix this, shift it by 8 as usual and clear its bit 0.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Woojung Huh <woojung.huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/mv88e6060.c b/drivers/net/dsa/mv88e6060.c
index dce7fa5..f123ed5 100644 (file)
--- a/drivers/net/dsa/mv88e6060.c
+++ b/drivers/net/dsa/mv88e6060.c
@@ -214,8 +214,14 @@ static int mv88e6060_setup(struct dsa_switch *ds)
 
 static int mv88e6060_set_addr(struct dsa_switch *ds, u8 *addr)
 {
-       /* Use the same MAC Address as FD Pause frames for all ports */
-       REG_WRITE(REG_GLOBAL, GLOBAL_MAC_01, (addr[0] << 9) | addr[1]);
+       u16 val = addr[0] << 8 | addr[1];
+
+       /* The multicast bit is always transmitted as a zero, so the switch uses
+        * bit 8 for "DiffAddr", where 0 means all ports transmit the same SA.
+        */
+       val &= 0xfeff;
+
+       REG_WRITE(REG_GLOBAL, GLOBAL_MAC_01, val);
        REG_WRITE(REG_GLOBAL, GLOBAL_MAC_23, (addr[2] << 8) | addr[3]);
        REG_WRITE(REG_GLOBAL, GLOBAL_MAC_45, (addr[4] << 8) | addr[5]);