[PATCH 1/2] r6040: check for absent PHY

[Florian Fainelli <florian@openwrt.org>]

Some devices have two R6040 MACs but the second one
is not wired to any PHY, therefore the interface is
just unusable. Warn the user about that and prevent
device from registering.

Tested-by: bifferos <bifferos@yahoo.co.uk>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
---
diff --git a/drivers/net/r6040.c b/drivers/net/r6040.c
index 6f97b47..b75b047 100644
--- a/drivers/net/r6040.c
+++ b/drivers/net/r6040.c
@@ -742,6 +742,14 @@ static int r6040_up(struct net_device *dev)
 	struct r6040_private *lp = netdev_priv(dev);
 	void __iomem *ioaddr = lp->base;
 	int ret;
+	u16 val;
+	
+	/* Check presence of a second PHY */
+	val = r6040_phy_read(ioaddr, lp->phy_addr, 2);
+	if (val == 0xFFFF) {
+		printk(KERN_ERR DRV_NAME " no second PHY attached\n");
+		return -EIO;
+	}
 
 	/* Initialise and alloc RX/TX buffers */
 	r6040_init_txbufs(dev);