Index: drivers/dahdi/dahdi-base.c
===================================================================
--- drivers/dahdi/dahdi-base.c	(revision 4600)
+++ drivers/dahdi/dahdi-base.c	(working copy)
@@ -4640,8 +4640,12 @@
 		chan->echotimer = 0;
 		spin_unlock_irqrestore(&chan->lock, flags);
 		if (ec_state) {
-			ec_current->echo_can_free(ec_state);
-			release_echocan(ec_current);
+			if (ec_current) {
+				ec_current->echo_can_free(ec_state);
+				release_echocan(ec_current);
+			} else {
+				WARN_ON(1);
+			}
 		}
 		hw_echocancel_off(chan);
 
@@ -4673,8 +4677,12 @@
 	chan->ec_current = NULL;
 	spin_unlock_irqrestore(&chan->lock, flags);
 	if (ec_state) {
-		ec_current->echo_can_free(ec_state);
-		release_echocan(ec_current);
+		if (ec_current) {
+			ec_current->echo_can_free(ec_state);
+			release_echocan(ec_current);
+		} else {
+			WARN_ON(1);
+		}
 	}
 	
 	ret = -ENODEV;
@@ -4713,12 +4721,13 @@
 		/* got the reference, copy the pointer and use it for making
 		   an echo canceler instance if possible */
 		ec_current = chan->ec_current;
-
-		if ((ret = ec_current->echo_can_create(ecp, params, &ec))) {
-			release_echocan(ec_current);
-
-			goto exit_with_free;
-		}
+		if (ec_current) {
+			ret = ec_current->echo_can_create(ecp, params, &ec);
+			if (ret) {
+				release_echocan(ec_current);
+				goto exit_with_free;
+			}
+		} 
 		
 		spin_lock_irqsave(&chan->lock, flags);
 		chan->echocancel = ecp->tap_length;