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authorBrian Norris <computersforpeace@gmail.com>2011-08-30 18:45:38 -0700
committerArtem Bityutskiy <artem.bityutskiy@intel.com>2011-09-11 15:13:38 +0300
commitc46f6483d21e93400e4a110de7902830173d53b0 (patch)
treebac45575c58963f4bc35d13b188c8ff5a32c9823 /drivers/mtd
parente9195edc59f33e9cabdd32a2959e927806670f45 (diff)
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.c14
-rw-r--r--drivers/mtd/nand/nand_base.c7
2 files changed, 14 insertions, 7 deletions
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index bcb7f05fd27..d0eaef67b9b 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 b61a7c7bd09..ad40607f5f2 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;