Index: firmware/target/arm/usb-s3c6400x.c
===================================================================
--- firmware/target/arm/usb-s3c6400x.c	(Revision 24215)
+++ firmware/target/arm/usb-s3c6400x.c	(Arbeitskopie)
@@ -50,6 +50,7 @@
 
 static struct ep_type endpoints[5];
 static struct usb_ctrlrequest ctrlreq USB_DEVBSS_ATTR;
+static unsigned char dummy_data[32] USB_DEVBSS_ATTR;
 
 int usb_drv_port_speed(void)
 {
@@ -291,7 +292,7 @@
     DOEPCTL(ep) |= 0x8000;  /* EPx OUT ACTIVE */
     int blocksize = usb_drv_port_speed() ? 512 : 64;
     int packets = (length + blocksize - 1) / blocksize;
-    if (!length) DIEPTSIZ(ep) = 1 << 19;  /* one empty packet */
+    if (!length) DOEPTSIZ(ep) = 1 << 19;  /* one empty packet */
     else DOEPTSIZ(ep) = length | (packets << 19);
     DOEPDMA(ep) = (uint32_t)ptr;
     clean_dcache();
@@ -301,6 +302,7 @@
 int usb_drv_send(int endpoint, void *ptr, int length)
 {
     endpoint &= 0x7f;
+    while(!endpoints[endpoint].done && endpoints[endpoint].busy);
     endpoints[endpoint].done = false;
     ep_send(endpoint, ptr, length);
     while (!endpoints[endpoint].done && endpoints[endpoint].busy)
@@ -310,12 +312,15 @@
 
 int usb_drv_send_nonblocking(int endpoint, void *ptr, int length)
 {
+    while(!endpoints[endpoint].done && endpoints[endpoint].busy);
     ep_send(endpoint & 0x7f, ptr, length);
     return 0;
 }
 
 int usb_drv_recv(int endpoint, void* ptr, int length)
 {
+    if(ptr==NULL) ptr = dummy_data;
+    while(!endpoints[endpoint].done && endpoints[endpoint].busy);
     ep_recv(endpoint & 0x7f, ptr, length);
     return 0;
 }