diff --git a/drivers/isdn/gigaset/asyncdata.c b/drivers/isdn/gigaset/asyncdata.c
index 8601b7a8f6a6..4f5dd9cf9e1b 100644
--- a/drivers/isdn/gigaset/asyncdata.c
+++ b/drivers/isdn/gigaset/asyncdata.c
@@ -98,7 +98,7 @@ static inline int lock_loop(unsigned char *src, int numbytes,
 	struct cardstate *cs = inbuf->cs;
 
 	gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response",
-			   numbytes, src, 0);
+			   numbytes, src);
 	gigaset_if_receive(cs, src, numbytes);
 
 	return numbytes;
diff --git a/drivers/isdn/gigaset/bas-gigaset.c b/drivers/isdn/gigaset/bas-gigaset.c
index b75f2f37c355..8cfd51863136 100644
--- a/drivers/isdn/gigaset/bas-gigaset.c
+++ b/drivers/isdn/gigaset/bas-gigaset.c
@@ -1756,7 +1756,7 @@ static int gigaset_write_cmd(struct cardstate *cs,
 
 	gigaset_dbg_buffer(atomic_read(&cs->mstate) != MS_LOCKED ?
 			     DEBUG_TRANSCMD : DEBUG_LOCKCMD,
-			   "CMD Transmit", len, buf, 0);
+			   "CMD Transmit", len, buf);
 
 	if (unlikely(!atomic_read(&cs->connected))) {
 		err("%s: disconnected", __func__);
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index 5155c5b07a06..e9bfcfd9f116 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -79,50 +79,34 @@ __u8 gigaset_invtab[256] = {
 EXPORT_SYMBOL_GPL(gigaset_invtab);
 
 void gigaset_dbg_buffer(enum debuglevel level, const unsigned char *msg,
-			size_t len, const unsigned char *buf, int from_user)
+			size_t len, const unsigned char *buf)
 {
 	unsigned char outbuf[80];
-	unsigned char inbuf[80 - 1];
 	unsigned char c;
-	size_t numin;
-	const unsigned char *in;
 	size_t space = sizeof outbuf - 1;
 	unsigned char *out = outbuf;
+	size_t numin = len;
 
-	if (!from_user) {
-		in = buf;
-		numin = len;
-	} else {
-		numin = len < sizeof inbuf ? len : sizeof inbuf;
-		in = inbuf;
-		if (copy_from_user(inbuf, (const unsigned char __user *) buf,
-				   numin)) {
-			gig_dbg(level, "%s (%u bytes) - copy_from_user failed",
-				msg, (unsigned) len);
-			return;
-		}
-	}
-
-	while (numin-- > 0) {
+	while (numin--) {
 		c = *buf++;
 		if (c == '~' || c == '^' || c == '\\') {
-			if (space-- <= 0)
+			if (!space--)
 				break;
 			*out++ = '\\';
 		}
 		if (c & 0x80) {
-			if (space-- <= 0)
+			if (!space--)
 				break;
 			*out++ = '~';
 			c ^= 0x80;
 		}
 		if (c < 0x20 || c == 0x7f) {
-			if (space-- <= 0)
+			if (!space--)
 				break;
 			*out++ = '^';
 			c ^= 0x40;
 		}
-		if (space-- <= 0)
+		if (!space--)
 			break;
 		*out++ = c;
 	}
diff --git a/drivers/isdn/gigaset/gigaset.h b/drivers/isdn/gigaset/gigaset.h
index 446a078224a9..7a44caca8a17 100644
--- a/drivers/isdn/gigaset/gigaset.h
+++ b/drivers/isdn/gigaset/gigaset.h
@@ -154,7 +154,7 @@ enum debuglevel { /* up to 24 bits (atomic_t) */
 #endif
 
 void gigaset_dbg_buffer(enum debuglevel level, const unsigned char *msg,
-			size_t len, const unsigned char *buf, int from_user);
+			size_t len, const unsigned char *buf);
 
 /* connection state */
 #define ZSAU_NONE			0
diff --git a/drivers/isdn/gigaset/interface.c b/drivers/isdn/gigaset/interface.c
index f3dce8c4831b..25750864d206 100644
--- a/drivers/isdn/gigaset/interface.c
+++ b/drivers/isdn/gigaset/interface.c
@@ -246,8 +246,6 @@ static int if_ioctl(struct tty_struct *tty, struct file *file,
 			break;
 		case GIGASET_BRKCHARS:
 			//FIXME test if MS_LOCKED
-			gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
-					   6, (const unsigned char *) arg, 1);
 			if (!atomic_read(&cs->connected)) {
 				gig_dbg(DEBUG_ANY,
 				    "can't communicate with unplugged device");
@@ -257,8 +255,11 @@ static int if_ioctl(struct tty_struct *tty, struct file *file,
 			retval = copy_from_user(&buf,
 					(const unsigned char __user *) arg, 6)
 				? -EFAULT : 0;
-			if (retval >= 0)
+			if (retval >= 0) {
+				gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
+						6, (const unsigned char *) arg);
 				retval = cs->ops->brkchars(cs, buf);
+			}
 			break;
 		case GIGASET_VERSION:
 			retval = copy_from_user(version,
diff --git a/drivers/isdn/gigaset/isocdata.c b/drivers/isdn/gigaset/isocdata.c
index 0b7e5b610cc9..5f2f47fdc045 100644
--- a/drivers/isdn/gigaset/isocdata.c
+++ b/drivers/isdn/gigaset/isocdata.c
@@ -957,11 +957,11 @@ void gigaset_isoc_input(struct inbuf_t *inbuf)
 
 		if (atomic_read(&cs->mstate) == MS_LOCKED) {
 			gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response",
-					   numbytes, src, 0);
+					   numbytes, src);
 			gigaset_if_receive(inbuf->cs, src, numbytes);
 		} else {
 			gigaset_dbg_buffer(DEBUG_CMD, "received response",
-					   numbytes, src, 0);
+					   numbytes, src);
 			cmd_loop(src, numbytes, inbuf);
 		}
 
diff --git a/drivers/isdn/gigaset/usb-gigaset.c b/drivers/isdn/gigaset/usb-gigaset.c
index e1a3eeb3c21a..6ae5df5f2b6a 100644
--- a/drivers/isdn/gigaset/usb-gigaset.c
+++ b/drivers/isdn/gigaset/usb-gigaset.c
@@ -500,7 +500,7 @@ static int gigaset_write_cmd(struct cardstate *cs, const unsigned char *buf,
 
 	gigaset_dbg_buffer(atomic_read(&cs->mstate) != MS_LOCKED ?
 			     DEBUG_TRANSCMD : DEBUG_LOCKCMD,
-			   "CMD Transmit", len, buf, 0);
+			   "CMD Transmit", len, buf);
 
 	if (!atomic_read(&cs->connected)) {
 		err("%s: not connected", __func__);
@@ -559,7 +559,7 @@ static int gigaset_brkchars(struct cardstate *cs, const unsigned char buf[6])
 #ifdef CONFIG_GIGASET_UNDOCREQ
 	struct usb_device *udev = cs->hw.usb->udev;
 
-	gigaset_dbg_buffer(DEBUG_USBREQ, "brkchars", 6, buf, 0);
+	gigaset_dbg_buffer(DEBUG_USBREQ, "brkchars", 6, buf);
 	memcpy(cs->hw.usb->bchars, buf, 6);
 	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 0x19, 0x41,
 			       0, 0, &buf, 6, 2000);