you can add it after our efika's patch collection (sven-efika+cruxppc-2007.01.25.tar.gz )...
for a while you can download it (the 33th patch) here:
http://acrux.homelinux.org/files/0033-E ... pl_aln.txt
Code:
--- half/drivers/net/fec_mpc52xx/fec.c	2007-03-08 18:02:54.000000000 +0100
+++ full/drivers/net/fec_mpc52xx/fec.c	2007-03-08 18:06:45.000000000 +0100
@@ -525,7 +525,7 @@
 	priv->phy_speed = ((bd->bi_ipbfreq >> 20) / 5) << 1;
 #endif
 
-	fec_restart(dev, 0);	/* always use half duplex mode only */
+	fec_restart(dev, 1);	/* now use full duplex mode only */
 	/*
 	 * Read MIB counters in order to reset them,
 	 * then zero all the stats fields in memory
--- half/drivers/net/fec_mpc52xx/fec_phy.c	2007-03-08 18:02:54.000000000 +0100
+++ full/drivers/net/fec_mpc52xx/fec_phy.c	2007-03-08 18:08:13.000000000 +0100
@@ -227,8 +227,8 @@
 	"GENERIC",
 
 	(const phy_cmd_t []) {	/* config */
-		/* advertise only half-duplex capabilities */
-		{ mk_mii_write(MII_ADVERTISE, MII_ADVERTISE_HALF),
+		/* advertise only full-duplex capabilities */
+		{ mk_mii_write(MII_ADVERTISE, MII_ADVERTISE_ALL),
 			mii_parse_anar },
 
 		/* enable auto-negotiation */
--
it seems to work fine on our test kernel-2.6.20.2, btw this patch is only for testing pourpose.
greetz,
The Crux PPC Team