| Message ID | 20210120101750.1163-3-miquel.raynal@bootlin.com |
|---|---|
| State | Changes Requested |
| Delegated to: | Miquel Raynal |
| Headers | show |
| Series | Fix OMAP2 ECC/OOB layout logic | expand |
On Wed, 20 Jan 2021 11:17:50 +0100 Miquel Raynal <miquel.raynal@bootlin.com> wrote: > The OMAP driver may leverage software BCH logic to locate errors while > using its own hardware to detect the presence of errors. This is > achieved with a "mixed" mode which initializes manually the software > BCH internal logic while providing its own OOB layout. > > The issue here comes from the fact that the BCH driver has been > updated to only use generic NAND objects, and no longer depend on raw > NAND structures as it is usable from SPI-NAND as well. However, at the > end of the BCH context initialization, the driver checks the validity > of the OOB layout. At this stage, the raw NAND fields have not been > populated yet while being used by the layout helpers, leading to an > invalid layout. > > The solution here is to use the fields from the generic ECC structures > which have already been updated and will always be valid instead of > the raw NAND ones. > > Note: I don't know which commit exactly triggered the error, but the > entire migration to a generic BCH driver got merged in one go, so this > should not be a problem for stable backports. > > Reported-by: Adam Ford <aford173@gmail.com> > Fixes: 80fe603160a4 ("mtd: nand: ecc-bch: Stop using raw NAND structures") > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> > --- > drivers/mtd/nand/raw/omap2.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/drivers/mtd/nand/raw/omap2.c b/drivers/mtd/nand/raw/omap2.c > index fbb9955f2467..fd09b2a30abb 100644 > --- a/drivers/mtd/nand/raw/omap2.c > +++ b/drivers/mtd/nand/raw/omap2.c > @@ -1866,18 +1866,20 @@ static const struct mtd_ooblayout_ops omap_ooblayout_ops = { > static int omap_sw_ooblayout_ecc(struct mtd_info *mtd, int section, > struct mtd_oob_region *oobregion) > { > - struct nand_chip *chip = mtd_to_nand(mtd); > + struct nand_device *nand = mtd_to_nanddev(mtd); > + unsigned int nsteps = nanddev_get_ecc_nsteps(nand); > + unsigned int ecc_bytes = nand->ecc.ctx.total / nsteps; I'd recommend adding a helper for that one too (nanddev_ecc_bytes_per_step()?). This being said, I think you're better off applying v1 (which is self-contained) and keeping this refactor for the next release. > int off = BADBLOCK_MARKER_LENGTH; > > - if (section >= chip->ecc.steps) > + if (section >= nsteps) > return -ERANGE; > > /* > * When SW correction is employed, one OMAP specific marker byte is > * reserved after each ECC step. > */ > - oobregion->offset = off + (section * (chip->ecc.bytes + 1)); > - oobregion->length = chip->ecc.bytes; > + oobregion->offset = off + (section * (ecc_bytes + 1)); > + oobregion->length = ecc_bytes; > > return 0; > } > @@ -1885,7 +1887,9 @@ static int omap_sw_ooblayout_ecc(struct mtd_info *mtd, int section, > static int omap_sw_ooblayout_free(struct mtd_info *mtd, int section, > struct mtd_oob_region *oobregion) > { > - struct nand_chip *chip = mtd_to_nand(mtd); > + struct nand_device *nand = mtd_to_nanddev(mtd); > + unsigned int nsteps = nanddev_get_ecc_nsteps(nand); > + unsigned int ecc_bytes = nand->ecc.ctx.total / nsteps; > int off = BADBLOCK_MARKER_LENGTH; > > if (section) > @@ -1895,7 +1899,7 @@ static int omap_sw_ooblayout_free(struct mtd_info *mtd, int section, > * When SW correction is employed, one OMAP specific marker byte is > * reserved after each ECC step. > */ > - off += ((chip->ecc.bytes + 1) * chip->ecc.steps); > + off += ((ecc_bytes + 1) * nsteps); > if (off >= mtd->oobsize) > return -ERANGE; >
diff --git a/drivers/mtd/nand/raw/omap2.c b/drivers/mtd/nand/raw/omap2.c index fbb9955f2467..fd09b2a30abb 100644 --- a/drivers/mtd/nand/raw/omap2.c +++ b/drivers/mtd/nand/raw/omap2.c @@ -1866,18 +1866,20 @@ static const struct mtd_ooblayout_ops omap_ooblayout_ops = { static int omap_sw_ooblayout_ecc(struct mtd_info *mtd, int section, struct mtd_oob_region *oobregion) { - struct nand_chip *chip = mtd_to_nand(mtd); + struct nand_device *nand = mtd_to_nanddev(mtd); + unsigned int nsteps = nanddev_get_ecc_nsteps(nand); + unsigned int ecc_bytes = nand->ecc.ctx.total / nsteps; int off = BADBLOCK_MARKER_LENGTH; - if (section >= chip->ecc.steps) + if (section >= nsteps) return -ERANGE; /* * When SW correction is employed, one OMAP specific marker byte is * reserved after each ECC step. */ - oobregion->offset = off + (section * (chip->ecc.bytes + 1)); - oobregion->length = chip->ecc.bytes; + oobregion->offset = off + (section * (ecc_bytes + 1)); + oobregion->length = ecc_bytes; return 0; } @@ -1885,7 +1887,9 @@ static int omap_sw_ooblayout_ecc(struct mtd_info *mtd, int section, static int omap_sw_ooblayout_free(struct mtd_info *mtd, int section, struct mtd_oob_region *oobregion) { - struct nand_chip *chip = mtd_to_nand(mtd); + struct nand_device *nand = mtd_to_nanddev(mtd); + unsigned int nsteps = nanddev_get_ecc_nsteps(nand); + unsigned int ecc_bytes = nand->ecc.ctx.total / nsteps; int off = BADBLOCK_MARKER_LENGTH; if (section) @@ -1895,7 +1899,7 @@ static int omap_sw_ooblayout_free(struct mtd_info *mtd, int section, * When SW correction is employed, one OMAP specific marker byte is * reserved after each ECC step. */ - off += ((chip->ecc.bytes + 1) * chip->ecc.steps); + off += ((ecc_bytes + 1) * nsteps); if (off >= mtd->oobsize) return -ERANGE;
The OMAP driver may leverage software BCH logic to locate errors while using its own hardware to detect the presence of errors. This is achieved with a "mixed" mode which initializes manually the software BCH internal logic while providing its own OOB layout. The issue here comes from the fact that the BCH driver has been updated to only use generic NAND objects, and no longer depend on raw NAND structures as it is usable from SPI-NAND as well. However, at the end of the BCH context initialization, the driver checks the validity of the OOB layout. At this stage, the raw NAND fields have not been populated yet while being used by the layout helpers, leading to an invalid layout. The solution here is to use the fields from the generic ECC structures which have already been updated and will always be valid instead of the raw NAND ones. Note: I don't know which commit exactly triggered the error, but the entire migration to a generic BCH driver got merged in one go, so this should not be a problem for stable backports. Reported-by: Adam Ford <aford173@gmail.com> Fixes: 80fe603160a4 ("mtd: nand: ecc-bch: Stop using raw NAND structures") Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> --- drivers/mtd/nand/raw/omap2.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)