[PATCH v2 1/2] ARM: kirkwood: Ensure that kirkwood_ge0[01]_init() finds its clock

[Jason Gunthorpe]

On Sun, Jan 27, 2013 at 11:52:41AM +0100, Sebastian Hesselbarth wrote:

> I agree that loosing the MAC address _is_ an issue but there must
> be another way to retain it during gated ge clocks than not gate the
> clocks at all.
> 
> I can think of some ways to retain it but don't know what is the most
> common with linux:
> - make u-boot pass it through cmdline and let mv643xx get it from there
> - have kirkwood's common code grab it before clk gates kick in

The cannonical solution here is to have a DT attribute
'local-mac-address' that is filled in by the bootloader rather than
attempting to pass the mac address to the kernel through the ethernet
controller registers.

Until the bootloaders are fixed a reasonable hack is to have the
platform startup code look for an all-zeros local-mac-address in the
DT and if found then copy the MAC from the ethernet registers into the
DT. Then the ethernet driver can safely be a module since the MAC is
captured in the DT.

I've been using this patch here on top of the original Ian Molton
patch.

Jason: Can you include something like this as well?

diff --git a/drivers/net/ethernet/marvell/mv643xx_eth.c b/drivers/net/ethernet/marvell/mv643xx_eth.c
index 7048d7c..2b2cfcb 100644
--- a/drivers/net/ethernet/marvell/mv643xx_eth.c
+++ b/drivers/net/ethernet/marvell/mv643xx_eth.c
@@ -2891,6 +2891,8 @@ static int mv643xx_eth_probe(struct platform_device *pdev)
 	struct mv643xx_eth_private *mp;
 	struct net_device *dev;
 	struct resource *res;
+	const u8 *mac;
+	int len;
 	int err;
 
 	if (pdev->dev.of_node) {
@@ -2912,6 +2914,10 @@ static int mv643xx_eth_probe(struct platform_device *pdev)
 		else
 			pd->phy_addr = MV643XX_ETH_PHY_ADDR_DEFAULT;
 
+		mac = of_get_property(pdev->dev.of_node, "local-mac-address", &len);
+		if (mac && len == 6)
+		    memcpy(pd->mac_addr, mac, sizeof pd->mac_addr);
+
 		np = of_parse_phandle(pdev->dev.of_node, "mdio", 0);
 		if (np) {
 			pd->shared = of_find_device_by_node(np);
-- 
1.7.5.4