mtd: spinand: Allow the case where there is no ECC engine

Even if this is not supposed to happen, there is no reason to fail the
probe if it was explicitly requested to use no ECC engine at all (for
instance, during development). This condition is met by just
commenting out the error on the OOB free bytes count after the
assignation of an ECC engine if none was provided (any other situation
would error out much earlier anyway).
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201001102014.20100-5-miquel.raynal@bootlin.com

drivers/mtd/nand/ecc.c

@@ -105,7 +105,7 @@
  */
 int nand_ecc_init_ctx(struct nand_device *nand)
 {
-	if (!nand->ecc.engine->ops->init_ctx)
+	if (!nand->ecc.engine || !nand->ecc.engine->ops->init_ctx)
 		return 0;
 
 	return nand->ecc.engine->ops->init_ctx(nand);
@@ -118,7 +118,7 @@ EXPORT_SYMBOL(nand_ecc_init_ctx);
  */
 void nand_ecc_cleanup_ctx(struct nand_device *nand)
 {
-	if (nand->ecc.engine->ops->cleanup_ctx)
+	if (nand->ecc.engine && nand->ecc.engine->ops->cleanup_ctx)
 		nand->ecc.engine->ops->cleanup_ctx(nand);
 }
 EXPORT_SYMBOL(nand_ecc_cleanup_ctx);
@@ -131,7 +131,7 @@ EXPORT_SYMBOL(nand_ecc_cleanup_ctx);
 int nand_ecc_prepare_io_req(struct nand_device *nand,
 			    struct nand_page_io_req *req)
 {
-	if (!nand->ecc.engine->ops->prepare_io_req)
+	if (!nand->ecc.engine || !nand->ecc.engine->ops->prepare_io_req)
 		return 0;
 
 	return nand->ecc.engine->ops->prepare_io_req(nand, req);
@@ -146,7 +146,7 @@ EXPORT_SYMBOL(nand_ecc_prepare_io_req);
 int nand_ecc_finish_io_req(struct nand_device *nand,
 			   struct nand_page_io_req *req)
 {
-	if (!nand->ecc.engine->ops->finish_io_req)
+	if (!nand->ecc.engine || !nand->ecc.engine->ops->finish_io_req)
 		return 0;
 
 	return nand->ecc.engine->ops->finish_io_req(nand, req);

drivers/mtd/nand/spi/core.c

@@ -1160,9 +1160,11 @@ static int spinand_init(struct spinand_device *spinand)
 	mtd->_erase = spinand_mtd_erase;
 	mtd->_max_bad_blocks = nanddev_mtd_max_bad_blocks;
 
-	ret = mtd_ooblayout_count_freebytes(mtd);
-	if (ret < 0)
-		goto err_cleanup_ecc_engine;
+	if (nand->ecc.engine) {
+		ret = mtd_ooblayout_count_freebytes(mtd);
+		if (ret < 0)
+			goto err_cleanup_ecc_engine;
+	}
 
 	mtd->oobavail = ret;