diff --git a/fthd_buffer.c b/fthd_buffer.c
index 2c06b6a..2a991e5 100644
--- a/fthd_buffer.c
+++ b/fthd_buffer.c
@@ -89,18 +89,18 @@ struct iommu_obj *iommu_allocate_sgtable(struct fthd_private *dev_priv,
 		
 		for (dma_length = 0; dma_length < sg_dma_len(sg);
 		     dma_length += 0x1000) {
-			// pr_debug("IOMMU %08x -> %08llx (dma length %d)\n", pos, dma_addr, dma_length);
 			FTHD_S2_REG_WRITE(dma_addr++, pos);
 			pos += 4;
 		}
 	}
 
-	pr_debug("allocated %d pages @ %p / offset %d\n", obj->size, obj, obj->offset);
+	pr_debug("allocated %d pages @ %p / offset %d\n", obj->size,
+		 obj, obj->offset);
 
 	return obj;
 }
 
-void iommu_free(struct fthd_private *dev_priv, struct iommu_obj *obj)
+void fthd_iommu_free(struct fthd_private *dev_priv, struct iommu_obj *obj)
 {
 	int i;
 	pr_debug("freeing %p\n", obj);
diff --git a/fthd_buffer.h b/fthd_buffer.h
index 4a75938..52e38c7 100644
--- a/fthd_buffer.h
+++ b/fthd_buffer.h
@@ -79,5 +79,5 @@ extern void fthd_buffer_exit(struct fthd_private *dev_priv);
 extern void fthd_buffer_return_handler(struct fthd_private *dev_priv, u32 offset, int size);
 extern void fthd_buffer_queued_handler(struct fthd_private *dev_priv, u32 offset);
 extern struct iommu_obj *iommu_allocate_sgtable(struct fthd_private *dev_priv, struct sg_table *);
-extern void iommu_free(struct fthd_private *dev_priv, struct iommu_obj *obj);
+extern void fthd_iommu_free(struct fthd_private *dev_priv, struct iommu_obj *obj);
 #endif
diff --git a/fthd_v4l2.c b/fthd_v4l2.c
index ca8a759..2d4f266 100644
--- a/fthd_v4l2.c
+++ b/fthd_v4l2.c
@@ -87,7 +87,7 @@ static void fthd_buffer_cleanup(struct vb2_buffer *vb)
 	ctx->vb = NULL;
 	isp_mem_destroy(ctx->dma_desc_obj);
 	for (i = 0; i < dev_priv->fmt.planes; i++) {
-		iommu_free(dev_priv, ctx->plane[i]);
+		fthd_iommu_free(dev_priv, ctx->plane[i]);
 		ctx->plane[i] = NULL;
 	}
 	ctx->dma_desc_obj = NULL;