diff --git a/[refs] b/[refs]
index 053631ab7ad6..b071b37ee082 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 477116e69dc48aaa70cca47668cd4aa82f39e05c
+refs/heads/master: eac141deb4f0136059372923ac3f0eab0bef5bce
diff --git a/trunk/drivers/isdn/hardware/avm/c4.c b/trunk/drivers/isdn/hardware/avm/c4.c
index 8710cf6214d9..4bbbbe688077 100644
--- a/trunk/drivers/isdn/hardware/avm/c4.c
+++ b/trunk/drivers/isdn/hardware/avm/c4.c
@@ -678,7 +678,9 @@ static irqreturn_t c4_handle_interrupt(avmcard *card)
                 for (i=0; i < card->nr_controllers; i++) {
 			avmctrl_info *cinfo = &card->ctrlinfo[i];
 			memset(cinfo->version, 0, sizeof(cinfo->version));
+			spin_lock_irqsave(&card->lock, flags);
 			capilib_release(&cinfo->ncci_head);
+			spin_unlock_irqrestore(&card->lock, flags);
 			capi_ctr_reseted(&cinfo->capi_ctrl);
 		}
 		card->nlogcontr = 0;