[PATCH v2 4/5] net: marvell: prestera: force good base mac

[Elad Nachman <enachman@marvell.com>]

From: Elad Nachman <enachman@marvell.com>

The switching ASIC router HW unit MAC Source Address is configured with
40-bits of MAC base address in its registers (done in the firmware code),
requiring all ports doing L3 routing in HW to have the same upper 40-bit
MAC address.

Since each switchport MAC address uses the switch base mac address and
then adds the physical port number to it, Force the last byte of the
switch base mac address to be at most 127, so when adding to it, we
will not wrap around the previous (more significant) mac address byte,
resulting in a warning message.

Fixes: 501ef3066c89 ("net: marvell: prestera: Add driver for Prestera family ASIC devices")
Signed-off-by: Elad Nachman <enachman@marvell.com>
---
 drivers/net/ethernet/marvell/prestera/prestera_main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/marvell/prestera/prestera_main.c b/drivers/net/ethernet/marvell/prestera/prestera_main.c
index bcaa8ea27b49..87d8fc4162b3 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera_main.c
+++ b/drivers/net/ethernet/marvell/prestera/prestera_main.c
@@ -860,6 +860,7 @@ static int prestera_switch_set_base_mac_addr(struct prestera_switch *sw)
 		ret = of_get_mac_address(sw->np, sw->base_mac);
 	if (!is_valid_ether_addr(sw->base_mac) || ret) {
 		eth_random_addr(sw->base_mac);
+		sw->base_mac[5] &= 0x7f;
 		dev_info(prestera_dev(sw), "using random base mac address\n");
 	}
 
-- 
2.25.1