On Mar 22, 2005, at 17:27, Jeff Garzik wrote:

quoted

 +int mii_check_gmii_support(struct mii_if_info *mii)
+{
+	int reg;
+
+	reg = mii->mdio_read(mii->dev, mii->phy_id, MII_BMSR);
+	if (reg & BMSR_HAS_EXTSTAT1000) {
+		reg = mii->mdio_read(mii->dev, mii->phy_id, MII_EXTSTAT1000);
+		if (reg & (ESR_1000_BASE_X_FD | ESR_1000_BASE_T_FD |
+			   ESR_1000_BASE_X_HD | ESR_1000_BASE_T_HD))
+			return 1;
+	}
+
+	return 0;

2) Reading a non-existent register will return all 1's in most cases, 
so I am not sure if this is the best test.

He reads a standard register (BMSR) to determine whether or not 
EXTSTAT1000 exists.  This is part of the 802.3 standard, so it should 
work.

Andy


Andy Fleming