--- drivers/dahdi/dahdi-base.c.orig	2011-01-12 15:38:44.000000000 +0200
+++ drivers/dahdi/dahdi-base.c	2011-01-12 20:35:47.000000000 +0200
@@ -49,7 +49,7 @@
 #include <linux/list.h>
 
 #ifdef HAVE_UNLOCKED_IOCTL
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #endif
 
 #include <linux/ppp_defs.h>
@@ -384,6 +384,10 @@
 static spinlock_t bigzaplock = SPIN_LOCK_UNLOCKED;
 #endif
 
+#ifdef HAVE_UNLOCKED_IOCTL
+static struct mutex dahdiioctllock;
+#endif
+
 struct dahdi_zone {
 	atomic_t refcount;
 	char name[40];	/* Informational, only */
@@ -5838,12 +5842,7 @@
 	return 0;
 }
 
-#ifdef HAVE_UNLOCKED_IOCTL
-static long dahdi_ioctl(struct file *file, unsigned int cmd, unsigned long data)
-#else
-static int dahdi_ioctl(struct inode *inode, struct file *file,
-		unsigned int cmd, unsigned long data)
-#endif
+static long dahdi_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 {
 	int unit = UNIT(file);
 	struct dahdi_chan *chan;
@@ -5851,7 +5850,7 @@
 	int ret;
 
 #ifdef HAVE_UNLOCKED_IOCTL
-	lock_kernel();
+	mutex_lock(&dahdiioctllock);
 #endif
 
 	if (!unit) {
@@ -5897,11 +5896,19 @@
 
 unlock_exit:
 #ifdef HAVE_UNLOCKED_IOCTL
-	unlock_kernel();
+	mutex_unlock(&dahdiioctllock);
 #endif
 	return ret;
 }
 
+#ifndef HAVE_UNLOCKED_IOCTL
+static int dahdi_ioctl(struct inode *inode, struct file *file,
+		unsigned int cmd, unsigned long data)
+{
+	return dahdi_unlocked_ioctl(file, cmd, data);
+}
+#endif
+
 #ifdef HAVE_COMPAT_IOCTL
 static long dahdi_ioctl_compat(struct file *file, unsigned int cmd,
 		unsigned long data)
@@ -5909,7 +5916,7 @@
 	if (cmd == DAHDI_SFCONFIG)
 		return -ENOTTY; /* Not supported yet */
 
-	return dahdi_ioctl(file, cmd, data);
+	return dahdi_unlocked_ioctl(file, cmd, data);
 }
 #endif
 
@@ -8603,7 +8610,7 @@
 	.open    = dahdi_open,
 	.release = dahdi_release,
 #ifdef HAVE_UNLOCKED_IOCTL
-	.unlocked_ioctl  = dahdi_ioctl,
+	.unlocked_ioctl  = dahdi_unlocked_ioctl,
 #ifdef HAVE_COMPAT_IOCTL
 	.compat_ioctl = dahdi_ioctl_compat,
 #endif