From: Frieder Schrempf frieder.schrempf@kontron.de

For reading and writing the bad block markers, spinand->oobbuf is currently used as a buffer for the marker bytes. During the underlying read and write operations to actually get/set the content of the OOB area, the content of spinand->oobbuf is reused and changed by accessing it through spinand->oobbuf and/or spinand->databuf.

This is a flaw in the original design of the SPI NAND core and at the latest from 13c15e07eedf ("mtd: spinand: Handle the case where PROGRAM LOAD does not reset the cache") on, it results in not having the bad block marker written at all, as the spinand->oobbuf is cleared to 0xff after setting the marker bytes to zero.

To fix it, we now just store the two bytes for the marker on the stack and let the read/write operations copy it from/to the page buffer later.

Fixes: 7529df465248 ("mtd: nand: Add core infrastructure to support SPI NANDs") Cc: stable@vger.kernel.org Signed-off-by: Frieder Schrempf frieder.schrempf@kontron.de Reviewed-by: Boris Brezillon boris.brezillon@collabora.com Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com Link: https://lore.kernel.org/linux-mtd/20200218100432.32433-2-frieder.schrempf@ko... --- drivers/mtd/nand/spi/core.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c index 93371fdde0..410ea2382d 100644 --- a/drivers/mtd/nand/spi/core.c +++ b/drivers/mtd/nand/spi/core.c @@ -655,16 +655,16 @@ static int spinand_mtd_write(struct mtd_info *mtd, loff_t to, static bool spinand_isbad(struct nand_device *nand, const struct nand_pos *pos) { struct spinand_device *spinand = nand_to_spinand(nand); + u8 marker[2] = { }; struct nand_page_io_req req = { .pos = *pos, - .ooblen = 2, + .ooblen = sizeof(marker), .ooboffs = 0, - .oobbuf.in = spinand->oobbuf, + .oobbuf.in = marker, .mode = MTD_OPS_RAW, }; int ret;

- memset(spinand->oobbuf, 0, 2); ret = spinand_select_target(spinand, pos->target); if (ret) return ret; @@ -673,7 +673,7 @@ static bool spinand_isbad(struct nand_device *nand, const struct nand_pos *pos) if (ret) return ret;

- if (spinand->oobbuf[0] != 0xff || spinand->oobbuf[1] != 0xff) + if (marker[0] != 0xff || marker[1] != 0xff) return true;

return false; @@ -702,11 +702,12 @@ static int spinand_mtd_block_isbad(struct mtd_info *mtd, loff_t offs) static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) { struct spinand_device *spinand = nand_to_spinand(nand); + u8 marker[2] = { }; struct nand_page_io_req req = { .pos = *pos, .ooboffs = 0, - .ooblen = 2, - .oobbuf.out = spinand->oobbuf, + .ooblen = sizeof(marker), + .oobbuf.out = marker, }; int ret;

@@ -723,7 +724,6 @@ static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) if (ret) return ret;

- memset(spinand->oobbuf, 0, 2); return spinand_write_page(spinand, &req); }