diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
index ceb33e3..c777016 100644
--- a/drivers/dfu/dfu.c
+++ b/drivers/dfu/dfu.c
@@ -339,9 +339,9 @@
 		if (dfu->i_buf_start == NULL)
 			return -ENOMEM;
 
-		dfu->r_left = dfu->get_medium_size(dfu);
-		if (dfu->r_left < 0)
-			return dfu->r_left;
+		ret = dfu->get_medium_size(dfu, &dfu->r_left);
+		if (ret < 0)
+			return ret;
 
 		debug("%s: %s %ld [B]\n", __func__, dfu->name, dfu->r_left);
 
diff --git a/drivers/dfu/dfu_mmc.c b/drivers/dfu/dfu_mmc.c
index 926ccbd..d918f95 100644
--- a/drivers/dfu/dfu_mmc.c
+++ b/drivers/dfu/dfu_mmc.c
@@ -209,23 +209,23 @@
 	return ret;
 }
 
-long dfu_get_medium_size_mmc(struct dfu_entity *dfu)
+int dfu_get_medium_size_mmc(struct dfu_entity *dfu, long *size)
 {
 	int ret;
-	long len;
 
 	switch (dfu->layout) {
 	case DFU_RAW_ADDR:
-		return dfu->data.mmc.lba_size * dfu->data.mmc.lba_blk_size;
+		*size = dfu->data.mmc.lba_size * dfu->data.mmc.lba_blk_size;
+		return 0;
 	case DFU_FS_FAT:
 	case DFU_FS_EXT4:
 		dfu_file_buf_filled = -1;
-		ret = mmc_file_op(DFU_OP_SIZE, dfu, NULL, &len);
+		ret = mmc_file_op(DFU_OP_SIZE, dfu, NULL, size);
 		if (ret < 0)
 			return ret;
-		if (len > CONFIG_SYS_DFU_MAX_FILE_SIZE)
+		if (*size > CONFIG_SYS_DFU_MAX_FILE_SIZE)
 			return -1;
-		return len;
+		return 0;
 	default:
 		printf("%s: Layout (%s) not (yet) supported!\n", __func__,
 		       dfu_get_layout(dfu->layout));
diff --git a/drivers/dfu/dfu_nand.c b/drivers/dfu/dfu_nand.c
index 97cd608..ed4ceb7 100644
--- a/drivers/dfu/dfu_nand.c
+++ b/drivers/dfu/dfu_nand.c
@@ -114,9 +114,11 @@
 	return ret;
 }
 
-long dfu_get_medium_size_nand(struct dfu_entity *dfu)
+int dfu_get_medium_size_nand(struct dfu_entity *dfu, long *size)
 {
-	return dfu->data.nand.size;
+	*size = dfu->data.nand.size;
+
+	return 0;
 }
 
 static int dfu_read_medium_nand(struct dfu_entity *dfu, u64 offset, void *buf,
diff --git a/drivers/dfu/dfu_ram.c b/drivers/dfu/dfu_ram.c
index c1b0021..b95cb9f 100644
--- a/drivers/dfu/dfu_ram.c
+++ b/drivers/dfu/dfu_ram.c
@@ -41,9 +41,11 @@
 	return dfu_transfer_medium_ram(DFU_OP_WRITE, dfu, offset, buf, len);
 }
 
-long dfu_get_medium_size_ram(struct dfu_entity *dfu)
+int dfu_get_medium_size_ram(struct dfu_entity *dfu, long *size)
 {
-	return dfu->data.ram.size;
+	*size = dfu->data.ram.size;
+
+	return 0;
 }
 
 static int dfu_read_medium_ram(struct dfu_entity *dfu, u64 offset,
diff --git a/drivers/dfu/dfu_sf.c b/drivers/dfu/dfu_sf.c
index b6d5fe2..2b26f2c 100644
--- a/drivers/dfu/dfu_sf.c
+++ b/drivers/dfu/dfu_sf.c
@@ -12,9 +12,11 @@
 #include <spi.h>
 #include <spi_flash.h>
 
-static long dfu_get_medium_size_sf(struct dfu_entity *dfu)
+static int dfu_get_medium_size_sf(struct dfu_entity *dfu, long *size)
 {
-	return dfu->data.sf.size;
+	*size = dfu->data.sf.size;
+
+	return 0;
 }
 
 static int dfu_read_medium_sf(struct dfu_entity *dfu, u64 offset, void *buf,