RE: [PATCH net-next v2 07/10] net/faraday: Read MAC address from chip

From: Gavin Shan

Sent: 15 July 2016 11:44
The device is assigned with random MAC address. It isn't reasonable.
An valid MAC address might have been provided by (uboot) firmware by
device-tree or in chip. It's reasonable to use it to maintain consistency.

This uses the MAC address from device-tree or that in the chip if it's
valid. Otherwise, a random MAC address is given as before.

...

+	m = ioread32(priv->base + FTGMAC100_OFFSET_MAC_MADR);
+	l = ioread32(priv->base + FTGMAC100_OFFSET_MAC_LADR);
+
+	mac[0] = (m >> 8) & 0xff;
+	mac[1] = m & 0xff;
+	mac[2] = (l >> 24) & 0xff;
+	mac[3] = (l >> 16) & 0xff;
+	mac[4] = (l >> 8) & 0xff;
+	mac[5] = l & 0xff;
+
+	if (!is_valid_ether_addr(mac)) {
+		mac[5] = (m >> 8) & 0xff;
+		mac[4] = m & 0xff;
+		mac[3] = (l >> 24) & 0xff;
+		mac[2] = (l >> 16) & 0xff;
+		mac[1] = (l >>  8) & 0xff;
+		mac[0] = l & 0xff;
+	}

...

That is horrid, not all byte reversed addresses will be invalid.

	David