| Message ID | 1314755147-17756-2-git-send-email-computersforpeace@gmail.com |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2011-08-30 at 18:45 -0700, Brian Norris wrote: > And if the buggy commit is going stable, this should go stable (or just > amend it) as well. Amended Adam's patch, thanks.
Brian Norris wrote: > For raw (i.e., w/o ECC) page writes (i.e., w/o OOB), we may > not have initialized and filled the chip->oob_poi buffer. > This can end up writing junk to the flash if we're not > careful. Say, for example, we use `nandwrite -n' (without > OOB). Then nand_do_write_ops calls > chip->write_page, which writes OOB data with some previous, junk data. > > This fixes a bug with this commit (from l2-mtd-2.6.git): > > commit a8ee364bbf14861d5d0af39c4da06c30441895fb > mtd: nand_base: always initialise oob_poi before writing OOB data That's annoying that I missed that. :( Thanks for spotting said issue and providing a fix. Regards Adam
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index d2ee68a..273e6a5 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -2227,6 +2227,9 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to, size_t len = min(oobwritelen, oobmaxlen); oob = nand_fill_oob(mtd, oob, len, ops); oobwritelen -= len; + } else { + /* We still need to erase leftover OOB data */ + memset(chip->oob_poi, 0xff, mtd->oobsize); } ret = chip->write_page(mtd, chip, wbuf, page, cached,
For raw (i.e., w/o ECC) page writes (i.e., w/o OOB), we may not have initialized and filled the chip->oob_poi buffer. This can end up writing junk to the flash if we're not careful. Say, for example, we use `nandwrite -n' (without OOB). Then nand_do_write_ops calls chip->write_page, which writes OOB data with some previous, junk data. This fixes a bug with this commit (from l2-mtd-2.6.git): commit a8ee364bbf14861d5d0af39c4da06c30441895fb mtd: nand_base: always initialise oob_poi before writing OOB data That commit removed the memset from under a conditional for: if (likely(!oob)) and moved it (indirectly) to the `nand_fill_oob()' function, which was under: if (unlikely(oob)) Though the "likely" and "unlikely" can be confusing, these are not the same conditions :) And if the buggy commit is going stable, this should go stable (or just amend it) as well. Signed-off-by: Brian Norris <computersforpeace@gmail.com> Cc: Adam Thomson <adam.thomson@alcatel-lucent.com> --- If the buggy commit is going into -stable, this should go -stable as well (or just amend the original). drivers/mtd/nand/nand_base.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)