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>
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index c7113a9..0b3d464 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -341,6 +341,7 @@
* @write_page: function to write a page according to the ECC generator
* requirements.
* @write_oob_raw: function to write chip OOB data without ECC
+ * @read_oob_raw: function to read chip OOB data without ECC
* @read_oob: function to read chip OOB data
* @write_oob: function to write chip OOB data
*/
@@ -371,6 +372,8 @@
const uint8_t *buf);
int (*write_oob_raw)(struct mtd_info *mtd, struct nand_chip *chip,
int page);
+ int (*read_oob_raw)(struct mtd_info *mtd, struct nand_chip *chip,
+ int page, int sndcmd);
int (*read_oob)(struct mtd_info *mtd, struct nand_chip *chip, int page,
int sndcmd);
int (*write_oob)(struct mtd_info *mtd, struct nand_chip *chip,