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| author | Brian Norris <computersforpeace@gmail.com> | 2011-08-31 03:45:38 +0200 |
|---|---|---|
| committer | Artem Bityutskiy <artem.bityutskiy@intel.com> | 2011-09-11 14:13:38 +0200 |
| commit | c46f6483d21e93400e4a110de7902830173d53b0 (patch) | |
| tree | bac45575c58963f4bc35d13b188c8ff5a32c9823 /drivers/mtd/mtdchar.c | |
| parent | mtd: nand: document nand_chip.oob_poi (diff) | |
| download | linux-c46f6483d21e93400e4a110de7902830173d53b0.tar.xz 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/mtdchar.c')
| -rw-r--r-- | drivers/mtd/mtdchar.c | 14 |
1 files changed, 8 insertions, 6 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; |