On Tue, 11 Feb 2020 16:35:33 +0000
Schrempf Frieder <frieder.schrempf@xxxxxxxxxx> wrote:
> From: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
>
> 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 MEM 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@xxxxxxxxxxxxxxx
> Signed-off-by: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
> ---
> drivers/mtd/nand/spi/core.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
> index 89f6beefb01c..5d267a67a5f7 100644
> --- a/drivers/mtd/nand/spi/core.c
> +++ b/drivers/mtd/nand/spi/core.c
> @@ -568,18 +568,18 @@ 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[] = { 0, 0 };
How about
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,
> };
>
> - memset(spinand->oobbuf, 0, 2);
> spinand_select_target(spinand, pos->target);
> spinand_read_page(spinand, &req, false);
> - if (spinand->oobbuf[0] != 0xff || spinand->oobbuf[1] != 0xff)
> + if (marker[0] != 0xff || marker[1] != 0xff)
> return true;
>
> return false;
> @@ -603,11 +603,12 @@ 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[] = { 0, 0 };
> struct nand_page_io_req req = {
> .pos = *pos,
> .ooboffs = 0,
> .ooblen = 2,
> - .oobbuf.out = spinand->oobbuf,
> + .oobbuf.out = marker,
Ditto.
> };
> int ret;
>
> @@ -622,7 +623,6 @@ static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos)
>
> spinand_erase_op(spinand, pos);
>
> - memset(spinand->oobbuf, 0, 2);
> return spinand_write_page(spinand, &req);
> }
>
With these minor things addressed
Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
