--- zzzz-none-000/linux-2.6.28.10/drivers/char/n_tty.c	2009-05-02 18:54:43.000000000 +0000
+++ fusiv-7390-686/linux-2.6.28.10/drivers/char/n_tty.c	2016-02-10 17:16:55.000000000 +0000
@@ -1495,6 +1495,7 @@
  *	This code must be sure never to sleep through a hangup.
  */
 
+unsigned int g_avm_console_open;
 static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
 			  const unsigned char *buf, size_t nr)
 {
@@ -1510,6 +1511,13 @@
 			return retval;
 	}
 
+    if (tty->driver->ops->is_avm_console) {
+        if (( ! g_avm_console_open) && tty->driver->ops->is_avm_console(tty)) {
+            b += nr;
+            goto skip_out;
+        }
+    }
+
 	add_wait_queue(&tty->write_wait, &wait);
 	while (1) {
 		set_current_state(TASK_INTERRUPTIBLE);
@@ -1565,6 +1573,7 @@
 break_out:
 	__set_current_state(TASK_RUNNING);
 	remove_wait_queue(&tty->write_wait, &wait);
+skip_out:
 	return (b - buf) ? b - buf : retval;
 }
 
@@ -1664,3 +1673,13 @@
 	.write_wakeup    = n_tty_write_wakeup
 };
 
+/*------------------------------------------------------------------------------------------*\
+ * keine Ausgaben auf der Console ohne g_avm_console_open=1
+ * n_tty_read schaltet die Ausgaben auf der Console wieder frei
+ * beim Kunden wird kein Read auf der Console erfolgen, also gibt es auch keine Ausgaben
+\*------------------------------------------------------------------------------------------*/
+static int setup_debug_console(char *p) {
+    g_avm_console_open = 1;
+    return 0;
+}
+__setup("debug_console", setup_debug_console);