Hi Matt, On Fri, Apr 14, 2017 at 11:32:05AM -0700, Matt Reimer wrote: > BCH error detection and correction was only looking at the first > of four syndrome polynomials, which meant it was failing to detect > and correct bitflips in the last 3/4 of the data. In effect, only > the first 512 bytes of a 2048 byte page were being protected by ECC. > > The syndrome polynomials (BCH error codes) are stored in the NAND's > OOB, each of which protects 512 bytes of data. The driver used > eccsteps = 1 which effectively made it only use the first polynomial, > and therefore was only protecting the first 512 bytes of the page. > > The fix is to pull over a bit of code from the kernel's > omap_correct_data() that sets eccsteps = 4 when the page size is 2048 > bytes and hardware ECC is being used. > > Signed-off-by: Matt Reimer <mreimer@xxxxxxxxxxxxxx> > --- > drivers/mtd/nand/nand_omap_gpmc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/mtd/nand/nand_omap_gpmc.c b/drivers/mtd/nand/nand_omap_gpmc.c > index 9d9d27e..2fe6a10 100644 > --- a/drivers/mtd/nand/nand_omap_gpmc.c > +++ b/drivers/mtd/nand/nand_omap_gpmc.c > @@ -302,7 +302,8 @@ static int omap_correct_bch(struct mtd_info *mtd, uint8_t *dat, > unsigned int err_loc[8]; > int select_4_8; > > - int eccsteps = oinfo->nand.ecc.steps; > + int eccsteps = (nand->ecc.mode == NAND_ECC_HW) && > + (nand->ecc.size == 2048) ? 4 : 1; Fixed up indention and applied, thanks Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
