diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 3c8c0232ce431..5641b9c8d50cd 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -258,9 +258,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
 	if (WARN_ON(!attach || !attach->dmabuf))
 		return ERR_PTR(-EINVAL);
 
-	mutex_lock(&attach->dmabuf->lock);
 	sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
-	mutex_unlock(&attach->dmabuf->lock);
 
 	return sg_table;
 }
@@ -282,10 +280,7 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
 	if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
 		return;
 
-	mutex_lock(&attach->dmabuf->lock);
 	attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,
 						direction);
-	mutex_unlock(&attach->dmabuf->lock);
-
 }
 EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index bc4203dc6e182..24e0f48287117 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -88,7 +88,7 @@ struct dma_buf {
 	struct file *file;
 	struct list_head attachments;
 	const struct dma_buf_ops *ops;
-	/* mutex to serialize list manipulation and other ops */
+	/* mutex to serialize list manipulation and attach/detach */
 	struct mutex lock;
 	void *priv;
 };