1 From c7c6a0f50f9ac3620c611ce06ba1f9fafea0444e Mon Sep 17 00:00:00 2001
2 From: Archit Taneja <architt@codeaurora.org>
3 Date: Mon, 3 Aug 2015 10:38:14 +0530
4 Subject: [PATCH 47/69] mtd: nand: Create a BBT flag to access bad block
7 Some controllers can access the factory bad block marker from OOB only
8 when they read it in raw mode. When ECC is enabled, these controllers
9 discard reading/writing bad block markers, preventing access to them
12 The bbt driver assumes MTD_OPS_PLACE_OOB when scanning for bad blocks.
13 This results in the nand driver's ecc->read_oob() op to be called, which
14 works with ECC enabled.
16 Create a new BBT option flag that tells nand_bbt to force the mode to
17 MTD_OPS_RAW. This would result in the correct op being called for the
18 underlying nand controller driver.
20 Reviewed-by: Andy Gross <agross@codeaurora.org>
21 Signed-off-by: Archit Taneja <architt@codeaurora.org>
23 drivers/mtd/nand/nand_base.c | 6 +++++-
24 drivers/mtd/nand/nand_bbt.c | 6 +++++-
25 include/linux/mtd/bbm.h | 6 ++++++
26 3 files changed, 16 insertions(+), 2 deletions(-)
28 --- a/drivers/mtd/nand/nand_base.c
29 +++ b/drivers/mtd/nand/nand_base.c
30 @@ -481,7 +481,11 @@ static int nand_default_block_markbad(st
32 ops.len = ops.ooblen = 1;
34 - ops.mode = MTD_OPS_PLACE_OOB;
36 + if (unlikely(chip->bbt_options & NAND_BBT_ACCESS_BBM_RAW))
37 + ops.mode = MTD_OPS_RAW;
39 + ops.mode = MTD_OPS_PLACE_OOB;
41 /* Write to first/last page(s) if necessary */
42 if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
43 --- a/drivers/mtd/nand/nand_bbt.c
44 +++ b/drivers/mtd/nand/nand_bbt.c
45 @@ -420,7 +420,11 @@ static int scan_block_fast(struct mtd_in
49 - ops.mode = MTD_OPS_PLACE_OOB;
51 + if (unlikely(bd->options & NAND_BBT_ACCESS_BBM_RAW))
52 + ops.mode = MTD_OPS_RAW;
54 + ops.mode = MTD_OPS_PLACE_OOB;
56 for (j = 0; j < numpages; j++) {
58 --- a/include/linux/mtd/bbm.h
59 +++ b/include/linux/mtd/bbm.h
60 @@ -116,6 +116,12 @@ struct nand_bbt_descr {
61 #define NAND_BBT_NO_OOB_BBM 0x00080000
64 + * Force MTD_OPS_RAW mode when trying to access bad block markes from OOB. To
65 + * be used by controllers which can access BBM only when ECC is disabled, i.e,
66 + * when in RAW access mode
68 +#define NAND_BBT_ACCESS_BBM_RAW 0x00100000
70 * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr
71 * was allocated dynamicaly and must be freed in nand_release(). Has no meaning
72 * in nand_chip.bbt_options.