diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c
index 1024c106c899..9a2b217941f7 100644
--- a/drivers/mtd/ubi/cdev.c
+++ b/drivers/mtd/ubi/cdev.c
@@ -113,7 +113,8 @@ static int vol_cdev_open(struct inode *inode, struct file *file)
 	else
 		mode = UBI_READONLY;
 
-	dbg_gen("open volume %d, mode %d", vol_id, mode);
+	dbg_gen("open device %d, volume %d, mode %d",
+	        ubi_num, vol_id, mode);
 
 	desc = ubi_open_volume(ubi_num, vol_id, mode);
 	if (IS_ERR(desc))
@@ -128,7 +129,8 @@ static int vol_cdev_release(struct inode *inode, struct file *file)
 	struct ubi_volume_desc *desc = file->private_data;
 	struct ubi_volume *vol = desc->vol;
 
-	dbg_gen("release volume %d, mode %d", vol->vol_id, desc->mode);
+	dbg_gen("release device %d, volume %d, mode %d",
+		vol->ubi->ubi_num, vol->vol_id, desc->mode);
 
 	if (vol->updating) {
 		ubi_warn("update of volume %d not finished, volume is damaged",
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index 4abbe573fa40..2675207c5fe3 100644
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -106,7 +106,7 @@ struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
 	struct ubi_device *ubi;
 	struct ubi_volume *vol;
 
-	dbg_gen("open device %d volume %d, mode %d", ubi_num, vol_id, mode);
+	dbg_gen("open device %d, volume %d, mode %d", ubi_num, vol_id, mode);
 
 	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
 		return ERR_PTR(-EINVAL);
@@ -196,6 +196,8 @@ struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
 	kfree(desc);
 out_put_ubi:
 	ubi_put_device(ubi);
+	dbg_err("cannot open device %d, volume %d, error %d",
+		ubi_num, vol_id, err);
 	return ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(ubi_open_volume);
@@ -215,7 +217,7 @@ struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
 	struct ubi_device *ubi;
 	struct ubi_volume_desc *ret;
 
-	dbg_gen("open volume %s, mode %d", name, mode);
+	dbg_gen("open device %d, volume %s, mode %d", ubi_num, name, mode);
 
 	if (!name)
 		return ERR_PTR(-EINVAL);
@@ -266,7 +268,8 @@ void ubi_close_volume(struct ubi_volume_desc *desc)
 	struct ubi_volume *vol = desc->vol;
 	struct ubi_device *ubi = vol->ubi;
 
-	dbg_gen("close volume %d, mode %d", vol->vol_id, desc->mode);
+	dbg_gen("close device %d, volume %d, mode %d",
+		ubi->ubi_num, vol->vol_id, desc->mode);
 
 	spin_lock(&ubi->volumes_lock);
 	switch (desc->mode) {
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 328c1242920e..419599d62b29 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -232,8 +232,8 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
 		req->vol_id = vol_id;
 	}
 
-	dbg_gen("volume ID %d, %llu bytes, type %d, name %s",
-		vol_id, (unsigned long long)req->bytes,
+	dbg_gen("create device %d, volume %d, %llu bytes, type %d, name %s",
+		ubi->ubi_num, vol_id, (unsigned long long)req->bytes,
 		(int)req->vol_type, req->name);
 
 	/* Ensure that this volume does not exist */
@@ -412,7 +412,7 @@ int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
 	struct ubi_device *ubi = vol->ubi;
 	int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;
 
-	dbg_gen("remove UBI volume %d", vol_id);
+	dbg_gen("remove device %d, volume %d", ubi->ubi_num, vol_id);
 	ubi_assert(desc->mode == UBI_EXCLUSIVE);
 	ubi_assert(vol == ubi->volumes[vol_id]);
 
@@ -498,8 +498,8 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
 	if (ubi->ro_mode)
 		return -EROFS;
 
-	dbg_gen("re-size volume %d to from %d to %d PEBs",
-		vol_id, vol->reserved_pebs, reserved_pebs);
+	dbg_gen("re-size device %d, volume %d to from %d to %d PEBs",
+		ubi->ubi_num, vol_id, vol->reserved_pebs, reserved_pebs);
 
 	if (vol->vol_type == UBI_STATIC_VOLUME &&
 	    reserved_pebs < vol->used_ebs) {