--- /dev/null
+--- linux-2.6.21.1.old/drivers/mmc/at91_mci.c 2007-06-05 11:08:39.000000000 +0200
++++ linux-2.6.21.1/drivers/mmc/at91_mci.c 2007-06-05 11:28:40.000000000 +0200
+@@ -79,8 +79,7 @@
+
+ #define DRIVER_NAME "at91_mci"
+
+-//#undef SUPPORT_4WIRE
+-#define SUPPORT_4WIRE
++#undef SUPPORT_4WIRE
+
+ #define FL_SENT_COMMAND (1 << 0)
+ #define FL_SENT_STOP (1 << 1)