| Message ID | 1347378650-3522-1-git-send-email-mikedunn@newsguy.com |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Sep 11, 2012 at 8:50 AM, Mike Dunn <mikedunn@newsguy.com> wrote: > diff --git a/drivers/mtd/nand/docg4.c b/drivers/mtd/nand/docg4.c > index 793921e..deb718c 100644 > --- a/drivers/mtd/nand/docg4.c > +++ b/drivers/mtd/nand/docg4.c > @@ -776,6 +776,8 @@ static int read_page(struct mtd_info *mtd, struct nand_chip *nand, > } > > writew(0, docptr + DOC_DATAEND); > + if (bits_corrected == -EBADMSG) /* uncorrectible errors */ s/uncorrectible/uncorrectable/ > + return 0; > return bits_corrected; > } > With that change: Acked-by: Brian Norris <computersforpeace@gmail.com> Also, not a blocker for this patch, but this made me look elsewhere in docg4.c: static int __init read_factory_bbt(struct mtd_info *mtd) { ... status = docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE); if (status) goto exit; This could cause problems if there are ever bitflips on the BBT page. Can the factory BBT contain bitflips? Brian
Hi Brian, thanks for the Ack. It seems I was careless with my own driver when I did the bitflip patches. BTW, the consequence of this oversight was seen when using mtdchar (e.g., mtd-utils 'nanddump') when uncorrectAble bitflips occurred. The userspace app just kept repeating the read call, because the prior call indicated that no data was read. On 09/14/2012 08:20 PM, Brian Norris wrote: >> + if (bits_corrected == -EBADMSG) /* uncorrectible errors */ > > s/uncorrectible/uncorrectable/ Ha! I actualy looked the word up in the dictionary, and either spelling is correct. But yours is more common. > >> + return 0; >> return bits_corrected; >> } >> > > With that change: > > Acked-by: Brian Norris <computersforpeace@gmail.com> > > Also, not a blocker for this patch, but this made me look elsewhere in docg4.c: > > static int __init read_factory_bbt(struct mtd_info *mtd) > { > ... > status = docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE); > if (status) > goto exit; > > This could cause problems if there are ever bitflips on the BBT page. > Can the factory BBT contain bitflips? Ah, yes, thank you for catching that!! Overlooked when docg4_read_page() was changed to return max bitflips; status should be tested for negative value. Should also try to recover from uncorrectable bitflips (I believe that table is stored redundantly). Thanks again, Mike
On Tue, 2012-09-11 at 08:50 -0700, Mike Dunn wrote: > Currently the docg4's ecc.read_page() method returns -EBADMSG when uncorrectible > bitflips occur. This is wrong; 0 should be returned in this case. An error > code should only be returned by this method in the case of a hardware error > (probably -EIO). > > Signed-off-by: Mike Dunn <mikedunn@newsguy.com> Pushed to l2-mtd.git, thanks!
diff --git a/drivers/mtd/nand/docg4.c b/drivers/mtd/nand/docg4.c index 793921e..deb718c 100644 --- a/drivers/mtd/nand/docg4.c +++ b/drivers/mtd/nand/docg4.c @@ -776,6 +776,8 @@ static int read_page(struct mtd_info *mtd, struct nand_chip *nand, } writew(0, docptr + DOC_DATAEND); + if (bits_corrected == -EBADMSG) /* uncorrectible errors */ + return 0; return bits_corrected; }
Currently the docg4's ecc.read_page() method returns -EBADMSG when uncorrectible bitflips occur. This is wrong; 0 should be returned in this case. An error code should only be returned by this method in the case of a hardware error (probably -EIO). Signed-off-by: Mike Dunn <mikedunn@newsguy.com> --- drivers/mtd/nand/docg4.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)