diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 479c2f2cf17f..8bf37da19663 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -304,24 +304,30 @@ static int spinand_write_to_cache_op(struct spinand_device *spinand,
 	struct nand_device *nand = spinand_to_nand(spinand);
 	struct mtd_info *mtd = nanddev_to_mtd(nand);
 	struct nand_page_io_req adjreq = *req;
-	unsigned int nbytes = 0;
-	void *buf = NULL;
+	void *buf = spinand->databuf;
+	unsigned int nbytes;
 	u16 column = 0;
 	int ret;
 
-	memset(spinand->databuf, 0xff,
-	       nanddev_page_size(nand) +
-	       nanddev_per_page_oobsize(nand));
+	/*
+	 * Looks like PROGRAM LOAD (AKA write cache) does not necessarily reset
+	 * the cache content to 0xFF (depends on vendor implementation), so we
+	 * must fill the page cache entirely even if we only want to program
+	 * the data portion of the page, otherwise we might corrupt the BBM or
+	 * user data previously programmed in OOB area.
+	 */
+	nbytes = nanddev_page_size(nand) + nanddev_per_page_oobsize(nand);
+	memset(spinand->databuf, 0xff, nbytes);
+	adjreq.dataoffs = 0;
+	adjreq.datalen = nanddev_page_size(nand);
+	adjreq.databuf.out = spinand->databuf;
+	adjreq.ooblen = nanddev_per_page_oobsize(nand);
+	adjreq.ooboffs = 0;
+	adjreq.oobbuf.out = spinand->oobbuf;
 
-	if (req->datalen) {
+	if (req->datalen)
 		memcpy(spinand->databuf + req->dataoffs, req->databuf.out,
 		       req->datalen);
-		adjreq.dataoffs = 0;
-		adjreq.datalen = nanddev_page_size(nand);
-		adjreq.databuf.out = spinand->databuf;
-		nbytes = adjreq.datalen;
-		buf = spinand->databuf;
-	}
 
 	if (req->ooblen) {
 		if (req->mode == MTD_OPS_AUTO_OOB)
@@ -332,14 +338,6 @@ static int spinand_write_to_cache_op(struct spinand_device *spinand,
 		else
 			memcpy(spinand->oobbuf + req->ooboffs, req->oobbuf.out,
 			       req->ooblen);
-
-		adjreq.ooblen = nanddev_per_page_oobsize(nand);
-		adjreq.ooboffs = 0;
-		nbytes += nanddev_per_page_oobsize(nand);
-		if (!buf) {
-			buf = spinand->oobbuf;
-			column = nanddev_page_size(nand);
-		}
 	}
 
 	spinand_cache_op_adjust_colum(spinand, &adjreq, &column);
@@ -370,8 +368,8 @@ static int spinand_write_to_cache_op(struct spinand_device *spinand,
 
 		/*
 		 * We need to use the RANDOM LOAD CACHE operation if there's
-		 * more than one iteration, because the LOAD operation resets
-		 * the cache to 0xff.
+		 * more than one iteration, because the LOAD operation might
+		 * reset the cache to 0xff.
 		 */
 		if (nbytes) {
 			column = op.addr.val;