diff --git a/target/linux/generic/patches-3.3/478-mtd-partial_eraseblock_unlock.patch b/target/linux/generic/patches-3.3/478-mtd-partial_eraseblock_unlock.patch
new file mode 100644
index 0000000000..de4481a93a
--- /dev/null
+++ b/target/linux/generic/patches-3.3/478-mtd-partial_eraseblock_unlock.patch
@@ -0,0 +1,18 @@
+--- a/drivers/mtd/mtdpart.c
++++ b/drivers/mtd/mtdpart.c
+@@ -356,7 +356,14 @@ static int part_unlock(struct mtd_info *
+ 	struct mtd_part *part = PART(mtd);
+ 	if ((len + ofs) > mtd->size)
+ 		return -EINVAL;
+-	return mtd_unlock(part->master, ofs + part->offset, len);
++
++	ofs += part->offset;
++	if (mtd->flags & MTD_ERASE_PARTIAL) {
++		/* round up len to next erasesize and round down offset to prev block */
++		len = (mtd_div_by_eb(len, part->master) + 1) * part->master->erasesize;
++		ofs &= ~(part->master->erasesize - 1);
++	}
++	return mtd_unlock(part->master, ofs, len);
+ }
+ 
+ static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)