diff --git a/drivers/mtd/ubi/gluebi.c b/drivers/mtd/ubi/gluebi.c
index 941bc3c..0b13fa2 100644
--- a/drivers/mtd/ubi/gluebi.c
+++ b/drivers/mtd/ubi/gluebi.c
@@ -171,10 +171,11 @@ static void gluebi_put_device(struct mtd_info *mtd)
 static int gluebi_read(struct mtd_info *mtd, loff_t from, size_t len,
 		       size_t *retlen, unsigned char *buf)
 {
-	int err = 0, lnum, offs, total_read;
+	int err = 0, lnum, offs;
+	size_t total_read;
 	struct gluebi_device *gluebi;
 
-	if (len < 0 || from < 0 || from + len > mtd->size)
+	if (from < 0 || from + len > mtd->size)
 		return -EINVAL;
 
 	gluebi = container_of(mtd, struct gluebi_device, mtd);
@@ -215,10 +216,11 @@ static int gluebi_read(struct mtd_info *mtd, loff_t from, size_t len,
 static int gluebi_write(struct mtd_info *mtd, loff_t to, size_t len,
 			size_t *retlen, const u_char *buf)
 {
-	int err = 0, lnum, offs, total_written;
+	size_t total_written;
+	int err = 0, lnum, offs;
 	struct gluebi_device *gluebi;
 
-	if (len < 0 || to < 0 || len + to > mtd->size)
+	if (to < 0 || len + to > mtd->size)
 		return -EINVAL;
 
 	gluebi = container_of(mtd, struct gluebi_device, mtd);
@@ -265,9 +267,9 @@ static int gluebi_erase(struct mtd_info *mtd, struct erase_info *instr)
 	int err, i, lnum, count;
 	struct gluebi_device *gluebi;
 
-	if (instr->addr < 0 || instr->addr > mtd->size - mtd->erasesize)
+	if (instr->addr > mtd->size - mtd->erasesize)
 		return -EINVAL;
-	if (instr->len < 0 || instr->addr + instr->len > mtd->size)
+	if (instr->addr + instr->len > mtd->size)
 		return -EINVAL;
 	if (mtd_mod_by_ws(instr->addr, mtd) || mtd_mod_by_ws(instr->len, mtd))
 		return -EINVAL;