diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index ed08e3946727edfacf8d345b7e22a847e9bd6920..79d98c9fa8a7528e8ac815e33dd480151462bd3e 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1421,7 +1421,10 @@ static int nand_check_erased_buf(void *buf, int len, int bitflips_threshold)
 
 	for (; len >= sizeof(long);
 	     len -= sizeof(long), bitmap += sizeof(long)) {
-		weight = hweight_long(*((unsigned long *)bitmap));
+		unsigned long d = *((unsigned long *)bitmap);
+		if (d == ~0UL)
+			continue;
+		weight = hweight_long(d);
 		bitflips += BITS_PER_LONG - weight;
 		if (unlikely(bitflips > bitflips_threshold))
 			return -EBADMSG;