According to the Winbond datasheet, the factory Bad Block Marker is strictly a single non-0xFF byte located at spare byte 0. The default spinand core assumes a 2-byte marker (byte 0 and 1).
However, after programming, upper-layer file systems (such as UBI) may utilize byte 1 for metadata. The default 2-byte check leads to false-positive bad block detections on valid blocks. Introduce a manufacturer-specific check (Winbond ID: 0xEF) to strictly evaluate only marker[0]. Signed-off-by: Zunyi Hu <[email protected]> --- drivers/mtd/nand/spi/core.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c index e5330958c7e..5395a1bdf68 100644 --- a/drivers/mtd/nand/spi/core.c +++ b/drivers/mtd/nand/spi/core.c @@ -676,6 +676,17 @@ static bool spinand_isbad(struct nand_device *nand, const struct nand_pos *pos) if (ret) return ret; + /* + * Winbond W25N (incl. W25N01G/GV): factory BBM is a single non-0xFF + * byte at spare byte 0 (see datasheet). Byte 1 may hold ECC or file + * system markers after programming — do not treat it as BBM. + */ + if (spinand->id.data[1] == 0xEF) { + if (marker[0] != 0xff) + return true; + return false; + } + if (marker[0] != 0xff || marker[1] != 0xff) return true; -- 2.17.1
