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author | Brian Norris <computersforpeace@gmail.com> | 2011-08-30 18:45:38 -0700 |
---|---|---|
committer | Artem Bityutskiy <artem.bityutskiy@intel.com> | 2011-09-11 15:13:38 +0300 |
commit | c46f6483d21e93400e4a110de7902830173d53b0 (patch) | |
tree | bac45575c58963f4bc35d13b188c8ff5a32c9823 /drivers/mtd | |
parent | e9195edc59f33e9cabdd32a2959e927806670f45 (diff) | |
download | linux-c46f6483d21e93400e4a110de7902830173d53b0.tar.gz linux-c46f6483d21e93400e4a110de7902830173d53b0.tar.bz2 linux-c46f6483d21e93400e4a110de7902830173d53b0.zip |
mtd: support reading OOB without ECC
This fixes issues with `nanddump -n' and the MEMREADOOB[64] ioctls on
hardware that performs error correction when reading only OOB data. A
driver for such hardware needs to know when we're doing a RAW vs. a
normal write, but mtd_do_read_oob does not pass such information to the
lower layers (e.g., NAND). We should pass MTD_OOB_RAW or MTD_OOB_PLACE
based on the MTD file mode.
For now, most drivers can get away with just setting:
chip->ecc.read_oob_raw = chip->ecc.read_oob
This is done by default; but for systems that behave as described above,
you must supply your own replacement function.
This was tested with nandsim as well as on actual SLC NAND.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Diffstat (limited to 'drivers/mtd')
-rw-r--r-- | drivers/mtd/mtdchar.c | 14 | ||||
-rw-r--r-- | drivers/mtd/nand/nand_base.c | 7 |
2 files changed, 14 insertions, 7 deletions
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index bcb7f05fd27b..d0eaef67b9bb 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -435,9 +435,11 @@ static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd, return ret; } -static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start, - uint32_t length, void __user *ptr, uint32_t __user *retp) +static int mtd_do_readoob(struct file *file, struct mtd_info *mtd, + uint64_t start, uint32_t length, void __user *ptr, + uint32_t __user *retp) { + struct mtd_file_info *mfi = file->private_data; struct mtd_oob_ops ops; int ret = 0; @@ -455,7 +457,7 @@ static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start, ops.ooblen = length; ops.ooboffs = start & (mtd->writesize - 1); ops.datbuf = NULL; - ops.mode = MTD_OOB_PLACE; + ops.mode = (mfi->mode == MTD_MODE_RAW) ? MTD_OOB_RAW : MTD_OOB_PLACE; if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs)) return -EINVAL; @@ -716,7 +718,7 @@ static int mtd_ioctl(struct file *file, u_int cmd, u_long arg) if (copy_from_user(&buf, argp, sizeof(buf))) ret = -EFAULT; else - ret = mtd_do_readoob(mtd, buf.start, buf.length, + ret = mtd_do_readoob(file, mtd, buf.start, buf.length, buf.ptr, &buf_user->start); break; } @@ -743,7 +745,7 @@ static int mtd_ioctl(struct file *file, u_int cmd, u_long arg) if (copy_from_user(&buf, argp, sizeof(buf))) ret = -EFAULT; else - ret = mtd_do_readoob(mtd, buf.start, buf.length, + ret = mtd_do_readoob(file, mtd, buf.start, buf.length, (void __user *)(uintptr_t)buf.usr_ptr, &buf_user->length); break; @@ -1029,7 +1031,7 @@ static long mtd_compat_ioctl(struct file *file, unsigned int cmd, if (copy_from_user(&buf, argp, sizeof(buf))) ret = -EFAULT; else - ret = mtd_do_readoob(mtd, buf.start, + ret = mtd_do_readoob(file, mtd, buf.start, buf.length, compat_ptr(buf.ptr), &buf_user->start); break; diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index b61a7c7bd097..ad40607f5f24 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -1787,7 +1787,10 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from, page = realpage & chip->pagemask; while (1) { - sndcmd = chip->ecc.read_oob(mtd, chip, page, sndcmd); + if (ops->mode == MTD_OOB_RAW) + sndcmd = chip->ecc.read_oob_raw(mtd, chip, page, sndcmd); + else + sndcmd = chip->ecc.read_oob(mtd, chip, page, sndcmd); len = min(len, readlen); buf = nand_transfer_oob(chip, buf, ops, len); @@ -3385,6 +3388,8 @@ int nand_scan_tail(struct mtd_info *mtd) } /* For many systems, the standard OOB write also works for raw */ + if (!chip->ecc.read_oob_raw) + chip->ecc.read_oob_raw = chip->ecc.read_oob; if (!chip->ecc.write_oob_raw) chip->ecc.write_oob_raw = chip->ecc.write_oob; |