diff --git a/drivers/scsi/arm/fas216.c b/drivers/scsi/arm/fas216.c
index cea34633b90a..d2581cb41ec8 100644
--- a/drivers/scsi/arm/fas216.c
+++ b/drivers/scsi/arm/fas216.c
@@ -2424,7 +2424,7 @@ int fas216_eh_abort(struct scsi_cmnd *SCpnt)
 	info->stats.aborts += 1;
 
 	printk(KERN_WARNING "scsi%d: abort command ", info->host->host_no);
-	__scsi_print_command(SCpnt->cmnd);
+	__scsi_print_command(SCpnt->cmnd, SCpnt->cmd_len);
 
 	print_debug_list();
 	fas216_dumpstate(info);
diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c
index 53621a34c5f9..226ef771efff 100644
--- a/drivers/scsi/ch.c
+++ b/drivers/scsi/ch.c
@@ -182,7 +182,7 @@ static int ch_find_errno(struct scsi_sense_hdr *sshdr)
 }
 
 static int
-ch_do_scsi(scsi_changer *ch, unsigned char *cmd,
+ch_do_scsi(scsi_changer *ch, unsigned char *cmd, int cmd_len,
 	   void *buffer, unsigned buflength,
 	   enum dma_data_direction direction)
 {
@@ -196,7 +196,7 @@ ch_do_scsi(scsi_changer *ch, unsigned char *cmd,
 	errno = 0;
 	if (debug) {
 		DPRINTK("command: ");
-		__scsi_print_command(cmd);
+		__scsi_print_command(cmd, cmd_len);
 	}
 
 	result = scsi_execute_req(ch->device, cmd, direction, buffer,
@@ -257,7 +257,8 @@ ch_read_element_status(scsi_changer *ch, u_int elem, char *data)
 	cmd[3] = elem        & 0xff;
 	cmd[5] = 1;
 	cmd[9] = 255;
-	if (0 == (result = ch_do_scsi(ch, cmd, buffer, 256, DMA_FROM_DEVICE))) {
+	if (0 == (result = ch_do_scsi(ch, cmd, 12,
+				      buffer, 256, DMA_FROM_DEVICE))) {
 		if (((buffer[16] << 8) | buffer[17]) != elem) {
 			DPRINTK("asked for element 0x%02x, got 0x%02x\n",
 				elem,(buffer[16] << 8) | buffer[17]);
@@ -287,7 +288,7 @@ ch_init_elem(scsi_changer *ch)
 	memset(cmd,0,sizeof(cmd));
 	cmd[0] = INITIALIZE_ELEMENT_STATUS;
 	cmd[1] = (ch->device->lun & 0x7) << 5;
-	err = ch_do_scsi(ch, cmd, NULL, 0, DMA_NONE);
+	err = ch_do_scsi(ch, cmd, 6, NULL, 0, DMA_NONE);
 	VPRINTK(KERN_INFO, "... finished\n");
 	return err;
 }
@@ -309,10 +310,10 @@ ch_readconfig(scsi_changer *ch)
 	cmd[1] = (ch->device->lun & 0x7) << 5;
 	cmd[2] = 0x1d;
 	cmd[4] = 255;
-	result = ch_do_scsi(ch, cmd, buffer, 255, DMA_FROM_DEVICE);
+	result = ch_do_scsi(ch, cmd, 10, buffer, 255, DMA_FROM_DEVICE);
 	if (0 != result) {
 		cmd[1] |= (1<<3);
-		result  = ch_do_scsi(ch, cmd, buffer, 255, DMA_FROM_DEVICE);
+		result  = ch_do_scsi(ch, cmd, 10, buffer, 255, DMA_FROM_DEVICE);
 	}
 	if (0 == result) {
 		ch->firsts[CHET_MT] =
@@ -437,7 +438,7 @@ ch_position(scsi_changer *ch, u_int trans, u_int elem, int rotate)
 	cmd[4]  = (elem  >> 8) & 0xff;
 	cmd[5]  =  elem        & 0xff;
 	cmd[8]  = rotate ? 1 : 0;
-	return ch_do_scsi(ch, cmd, NULL, 0, DMA_NONE);
+	return ch_do_scsi(ch, cmd, 10, NULL, 0, DMA_NONE);
 }
 
 static int
@@ -458,7 +459,7 @@ ch_move(scsi_changer *ch, u_int trans, u_int src, u_int dest, int rotate)
 	cmd[6]  = (dest  >> 8) & 0xff;
 	cmd[7]  =  dest        & 0xff;
 	cmd[10] = rotate ? 1 : 0;
-	return ch_do_scsi(ch, cmd, NULL,0, DMA_NONE);
+	return ch_do_scsi(ch, cmd, 12, NULL,0, DMA_NONE);
 }
 
 static int
@@ -484,7 +485,7 @@ ch_exchange(scsi_changer *ch, u_int trans, u_int src,
 	cmd[9]  =  dest2       & 0xff;
 	cmd[10] = (rotate1 ? 1 : 0) | (rotate2 ? 2 : 0);
 
-	return ch_do_scsi(ch, cmd, NULL,0, DMA_NONE);
+	return ch_do_scsi(ch, cmd, 12, NULL, 0, DMA_NONE);
 }
 
 static void
@@ -534,7 +535,7 @@ ch_set_voltag(scsi_changer *ch, u_int elem,
 	memcpy(buffer,tag,32);
 	ch_check_voltag(buffer);
 
-	result = ch_do_scsi(ch, cmd, buffer, 256, DMA_TO_DEVICE);
+	result = ch_do_scsi(ch, cmd, 12, buffer, 256, DMA_TO_DEVICE);
 	kfree(buffer);
 	return result;
 }
@@ -765,7 +766,8 @@ static long ch_ioctl(struct file *file,
 		ch_cmd[5] = 1;
 		ch_cmd[9] = 255;
 
-		result = ch_do_scsi(ch, ch_cmd, buffer, 256, DMA_FROM_DEVICE);
+		result = ch_do_scsi(ch, ch_cmd, 12,
+				    buffer, 256, DMA_FROM_DEVICE);
 		if (!result) {
 			cge.cge_status = buffer[18];
 			cge.cge_flags = 0;
diff --git a/drivers/scsi/constants.c b/drivers/scsi/constants.c
index dc1b18c821ed..a84ced0de02b 100644
--- a/drivers/scsi/constants.c
+++ b/drivers/scsi/constants.c
@@ -320,25 +320,21 @@ static bool scsi_opcode_sa_name(int opcode, int service_action,
 	return true;
 }
 
-/* attempt to guess cdb length if cdb_len==0 . No trailing linefeed. */
-static void print_opcode_name(unsigned char * cdbp, int cdb_len)
+static void print_opcode_name(const unsigned char *cdbp, size_t cdb_len)
 {
-	int sa, len, cdb0;
+	int sa, cdb0;
 	const char *cdb_name = NULL, *sa_name = NULL;
 
 	cdb0 = cdbp[0];
 	if (cdb0 == VARIABLE_LENGTH_CMD) {
-		len = scsi_varlen_cdb_length(cdbp);
-		if (len < 10) {
-			printk("short variable length command, "
-			       "len=%d ext_len=%d", len, cdb_len);
+		if (cdb_len < 10) {
+			printk("short variable length command, len=%zu",
+			       cdb_len);
 			return;
 		}
 		sa = (cdbp[8] << 8) + cdbp[9];
-	} else {
+	} else
 		sa = cdbp[1] & 0x1f;
-		len = cdb_len;
-	}
 
 	if (!scsi_opcode_sa_name(cdb0, sa, &cdb_name, &sa_name)) {
 		if (cdb_name)
@@ -356,18 +352,17 @@ static void print_opcode_name(unsigned char * cdbp, int cdb_len)
 			printk("%s, sa=0x%x", cdb_name, sa);
 		else
 			printk("cdb[0]=0x%x, sa=0x%x", cdb0, sa);
-
-		if (cdb_len > 0 && len != cdb_len)
-			printk(", in_cdb_len=%d, ext_len=%d", len, cdb_len);
 	}
 }
 
-void __scsi_print_command(unsigned char *cdb)
+void __scsi_print_command(const unsigned char *cdb, size_t cdb_len)
 {
 	int k, len;
 
-	print_opcode_name(cdb, 0);
+	print_opcode_name(cdb, cdb_len);
 	len = scsi_command_size(cdb);
+	if (cdb_len < len)
+		len = cdb_len;
 	/* print out all bytes in cdb */
 	for (k = 0; k < len; ++k)
 		printk(" %02x", cdb[k]);
diff --git a/drivers/scsi/sr_ioctl.c b/drivers/scsi/sr_ioctl.c
index 17e0c2b28a99..fb929fac22ba 100644
--- a/drivers/scsi/sr_ioctl.c
+++ b/drivers/scsi/sr_ioctl.c
@@ -257,14 +257,14 @@ int sr_do_ioctl(Scsi_CD *cd, struct packet_command *cgc)
 				/* sense: Invalid command operation code */
 				err = -EDRIVE_CANT_DO_THIS;
 #ifdef DEBUG
-			__scsi_print_command(cgc->cmd);
+			__scsi_print_command(cgc->cmd, CDROM_PACKET_SIZE);
 			scsi_print_sense_hdr(cd->device, cd->cdi.name, &sshdr);
 #endif
 			break;
 		default:
 			sr_printk(KERN_ERR, cd,
 				  "CDROM (ioctl) error, command: ");
-			__scsi_print_command(cgc->cmd);
+			__scsi_print_command(cgc->cmd, CDROM_PACKET_SIZE);
 			scsi_print_sense_hdr(cd->device, cd->cdi.name, &sshdr);
 			err = -EIO;
 		}
diff --git a/include/scsi/scsi_dbg.h b/include/scsi/scsi_dbg.h
index 386474ee53a1..81d041822229 100644
--- a/include/scsi/scsi_dbg.h
+++ b/include/scsi/scsi_dbg.h
@@ -6,7 +6,7 @@ struct scsi_device;
 struct scsi_sense_hdr;
 
 extern void scsi_print_command(struct scsi_cmnd *);
-extern void __scsi_print_command(unsigned char *);
+extern void __scsi_print_command(const unsigned char *, size_t);
 extern void scsi_show_extd_sense(const struct scsi_device *, const char *,
 				 unsigned char, unsigned char);
 extern void scsi_show_sense_hdr(const struct scsi_device *, const char *,