[PATCH 1/5] net: virtio-net: allow to set current MAC address

[Sascha Hauer <s.hauer@pengutronix.de>]

We currently can't change the current MAC address when VIRTIO_F_VERSION_1
is set, which is always the case. The barebox ethernet code calls set_ethaddr
with this exact MAC address it has just read from the hardware. Just
return successfully when the core wants to set the MAC address we
already have.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
---
 drivers/net/virtio.c | 34 ++++++++++++++++++++++------------
 1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/drivers/net/virtio.c b/drivers/net/virtio.c
index 8605f67ae2..1bc5e0cd90 100644
--- a/drivers/net/virtio.c
+++ b/drivers/net/virtio.c
@@ -135,29 +135,39 @@ static void virtio_net_stop(struct eth_device *dev)
 	 */
 }
 
+static int virtio_net_read_rom_hwaddr(struct eth_device *edev, unsigned char *adr)
+{
+	struct virtio_net_priv *priv = to_priv(edev);
+
+	virtio_cread_bytes(priv->vdev, offsetof(struct virtio_net_config, mac), adr, 6);
+
+	return 0;
+}
+
 static int virtio_net_write_hwaddr(struct eth_device *edev, const unsigned char *adr)
 {
 	struct virtio_net_priv *priv = to_priv(edev);
-	int i;
+	int i, ret;
 
 	/*
 	 * v1.0 compliant device's MAC address is set through control channel,
 	 * which we don't support for now.
 	 */
-	if (virtio_has_feature(priv->vdev, VIRTIO_F_VERSION_1))
-		return -ENOSYS;
-
-	for (i = 0; i < 6; i++)
-		virtio_cwrite8(priv->vdev, offsetof(struct virtio_net_config, mac) + i, adr[i]);
+	if (virtio_has_feature(priv->vdev, VIRTIO_F_VERSION_1)) {
+		char mac[6];
 
-	return 0;
-}
+		ret = virtio_net_read_rom_hwaddr(edev, mac);
+		if (ret)
+			return ret;
 
-static int virtio_net_read_rom_hwaddr(struct eth_device *edev, unsigned char *adr)
-{
-	struct virtio_net_priv *priv = to_priv(edev);
+		if (!memcmp(mac, adr, 5))
+			return 0;
+		else
+			return -ENOSYS;
+	}
 
-	virtio_cread_bytes(priv->vdev, offsetof(struct virtio_net_config, mac), adr, 6);
+	for (i = 0; i < 6; i++)
+		virtio_cwrite8(priv->vdev, offsetof(struct virtio_net_config, mac) + i, adr[i]);
 
 	return 0;
 }
-- 
2.39.2