| Message ID | 20180620074443.30235-1-boris.brezillon@bootlin.com |
|---|---|
| State | Accepted |
| Delegated to: | Miquel Raynal |
| Headers | show |
| Series | mtd: rawnand: micron: Update ecc_stats.corrected | expand |
Hi Boris, On Wed, 20 Jun 2018 09:44:43 +0200, Boris Brezillon <boris.brezillon@bootlin.com> wrote: > Even if we can't update ecc_stats.corrected with an accurate value we > should at least increase the number of bitflips so that MTD users can > know that there was some bitflips. > > Just add chip->ecc.strength to mtd->ecc_stats.corrected which should > account for the worst case situation. > > Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> > --- Shouldn't we consider this change as a fix? Thanks, Miquèl
On Wed, 20 Jun 2018 09:58:43 +0200 Miquel Raynal <miquel.raynal@bootlin.com> wrote: > Hi Boris, > > On Wed, 20 Jun 2018 09:44:43 +0200, Boris Brezillon > <boris.brezillon@bootlin.com> wrote: > > > Even if we can't update ecc_stats.corrected with an accurate value we > > should at least increase the number of bitflips so that MTD users can > > know that there was some bitflips. > > > > Just add chip->ecc.strength to mtd->ecc_stats.corrected which should > > account for the worst case situation. > > > > Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> > > --- > > Shouldn't we consider this change as a fix? It's not really fixing a bug, in that ecc_stats.corrected are already not accurate, they just give a hint about how often you fix bitflips on a NAND device. But if you think it should be backported, I can add the Fixes and Cc-stable tags.
Hi Boris, On Wed, 20 Jun 2018 10:04:44 +0200, Boris Brezillon <boris.brezillon@bootlin.com> wrote: > On Wed, 20 Jun 2018 09:58:43 +0200 > Miquel Raynal <miquel.raynal@bootlin.com> wrote: > > > Hi Boris, > > > > On Wed, 20 Jun 2018 09:44:43 +0200, Boris Brezillon > > <boris.brezillon@bootlin.com> wrote: > > > > > Even if we can't update ecc_stats.corrected with an accurate value we > > > should at least increase the number of bitflips so that MTD users can > > > know that there was some bitflips. > > > > > > Just add chip->ecc.strength to mtd->ecc_stats.corrected which should > > > account for the worst case situation. > > > > > > Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> > > > --- > > > > Shouldn't we consider this change as a fix? > > It's not really fixing a bug, in that ecc_stats.corrected are already > not accurate, they just give a hint about how often you fix bitflips > on a NAND device. But if you think it should be backported, I can add > the Fixes and Cc-stable tags. > It's fine for me. Applied to nand/next. Thanks, Miquèl
diff --git a/drivers/mtd/nand/raw/nand_micron.c b/drivers/mtd/nand/raw/nand_micron.c index 5ec4c90a637d..203faba0a9c1 100644 --- a/drivers/mtd/nand/raw/nand_micron.c +++ b/drivers/mtd/nand/raw/nand_micron.c @@ -137,18 +137,19 @@ micron_nand_read_page_on_die_ecc(struct mtd_info *mtd, struct nand_chip *chip, if (ret) goto out; - if (status & NAND_STATUS_FAIL) + if (status & NAND_STATUS_FAIL) { mtd->ecc_stats.failed++; - - /* - * The internal ECC doesn't tell us the number of bitflips - * that have been corrected, but tells us if it recommends to - * rewrite the block. If it's the case, then we pretend we had - * a number of bitflips equal to the ECC strength, which will - * hint the NAND core to rewrite the block. - */ - else if (status & NAND_STATUS_WRITE_RECOMMENDED) + } else if (status & NAND_STATUS_WRITE_RECOMMENDED) { + /* + * The internal ECC doesn't tell us the number of bitflips + * that have been corrected, but tells us if it recommends to + * rewrite the block. If it's the case, then we pretend we had + * a number of bitflips equal to the ECC strength, which will + * hint the NAND core to rewrite the block. + */ + mtd->ecc_stats.corrected += chip->ecc.strength; max_bitflips = chip->ecc.strength; + } ret = nand_read_data_op(chip, buf, mtd->writesize, false); if (!ret && oob_required)
Even if we can't update ecc_stats.corrected with an accurate value we should at least increase the number of bitflips so that MTD users can know that there was some bitflips. Just add chip->ecc.strength to mtd->ecc_stats.corrected which should account for the worst case situation. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> --- drivers/mtd/nand/raw/nand_micron.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-)