Messages in this thread | | | Date | Thu, 9 Nov 2023 12:09:34 +0300 | Subject | Re: [PATCH v1] mtd: rawnand: meson: handle OOB buffer according OOB layout | From | Arseniy Krasnov <> |
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Hello, thanks for review!
On 09.11.2023 11:06, Viacheslav Bocharov wrote: > Hi! > > On Thu, 2023-11-09 at 08:39 +0300, Arseniy Krasnov wrote: >> In case of MTD_OPS_AUTO_OOB mode, MTD/NAND layer fills/reads OOB buffer >> according current OOB layout so we need to follow it in the driver. >> >> Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com> >> --- >> drivers/mtd/nand/raw/meson_nand.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c >> index 561d46d860b7..0d4d358152d7 100644 >> --- a/drivers/mtd/nand/raw/meson_nand.c >> +++ b/drivers/mtd/nand/raw/meson_nand.c >> @@ -510,7 +510,7 @@ static void meson_nfc_set_user_byte(struct nand_chip *nand, u8 *oob_buf) >> __le64 *info; >> int i, count; >> >> - for (i = 0, count = 0; i < nand->ecc.steps; i++, count += 2) { >> + for (i = 0, count = 0; i < nand->ecc.steps; i++, count += (2 + nand->ecc.bytes)) { >> info = &meson_chip->info_buf[i]; >> *info |= oob_buf[count]; >> *info |= oob_buf[count + 1] << 8; > Seems something wrong with your logic here. > I think this code should most likely look like this: > > for (i = 0, count = 0; i < nand->ecc.steps; i++, count += nand->ecc.bytes) { > info = &meson_chip->info_buf[i]; > *info |= oob_buf[count]; > if (nand->ecc.bytes > 1) > *info |= oob_buf[count + 1] << 8; > }
For 64 bytes OOB and 512 bytes ECC this driver reports free areas as:
AA AA BB BB BB BB BB BB BB BB BB BB BB BB BB BB AA AA BB BB BB BB BB BB BB BB BB BB BB BB BB BB AA AA BB BB BB BB BB BB BB BB BB BB BB BB BB BB AA AA BB BB BB BB BB BB BB BB BB BB BB BB BB BB
where AA is free byte(user byte), BB - ECC codes. So to access user bytes we need bytes 0,1,16,17,32,33,48,49. nand->ecc.bytes == 14, so 'count' is increased at 16 every iteration, so i guess this is correct.
WDYT?
Thanks, Arseniy
> > >> @@ -523,7 +523,7 @@ static void meson_nfc_get_user_byte(struct nand_chip *nand, u8 *oob_buf) >> __le64 *info; >> int i, count; >> >> - for (i = 0, count = 0; i < nand->ecc.steps; i++, count += 2) { >> + for (i = 0, count = 0; i < nand->ecc.steps; i++, count += (2 + nand->ecc.bytes)) { >> info = &meson_chip->info_buf[i]; >> oob_buf[count] = *info; >> oob_buf[count + 1] = *info >> 8; > And there: > > for (i = 0, count = 0; i < nand->ecc.steps; i++, count += nand->ecc.bytes) { > info = &meson_chip->info_buf[i]; > oob_buf[count] = *info; > if (nand->ecc.bytes > 1) > oob_buf[count + 1] = *info >> 8; > } > > > This is more similar to the behavior of similar functions in the proprietary U-Boot. > > -- > Viacheslav Bocharov >
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