[PATCH 2/2] mtd: spinand: fix zero oobavail when no ECC engine is used

[Nuno Sá]

Commit 00c15b78b4b4 ("mtd: spinand: Allow the case where there is no
ECC engine") made the OOB free bytes count conditional on having an
ECC engine so that probing would not fail when none is requested.
However mtd->oobavail is still assigned from ret just after that
block, and ret is 0 there, so the device ends up advertising no
available OOB bytes at all.

mtd_oobavail() returns mtd->oobavail for MTD_OPS_AUTO_OOB, so a zero
value makes every automatic OOB access fail with -EINVAL. JFFS2 fares
worse: it keeps its cleanmarker in the OOB area on NAND and refuses to
mount outright, reporting "inconsistent device description".

No ECC engine also means no ooblayout was ever installed, which would
make the count return -ENOTSUPP, so install the same fallback layout
the on-die path already uses before counting unconditionally.

Fixes: 00c15b78b4b4 ("mtd: spinand: Allow the case where there is no ECC engine")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
---
 drivers/mtd/nand/spi/core.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 03ff43445693..8f3d12c5dd90 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1978,12 +1978,17 @@ static int spinand_init(struct spinand_device *spinand)
 			goto err_cleanup_ecc_engine;
 	}
 
-	if (nand->ecc.engine) {
-		ret = mtd_ooblayout_count_freebytes(mtd);
-		if (ret < 0)
-			goto err_cleanup_ecc_engine;
+	if (!nand->ecc.engine) {
+		if (spinand->eccinfo.ooblayout)
+			mtd_set_ooblayout(mtd, spinand->eccinfo.ooblayout);
+		else
+			mtd_set_ooblayout(mtd, &spinand_noecc_ooblayout);
 	}
 
+	ret = mtd_ooblayout_count_freebytes(mtd);
+	if (ret < 0)
+		goto err_cleanup_ecc_engine;
+
 	mtd->oobavail = ret;
 
 	/* Propagate ECC information to mtd_info */

-- 
2.55.0