target/linux/ipq806x/patches-4.14/0047-mtd-nand-Create-a-BBT-flag-to-access-bad-block-marke.patch

   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
   5  markers in raw mode
   6
   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
  10 altogether.
  11
  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.
  15
  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.
  19
  20 Reviewed-by: Andy Gross <agross@codeaurora.org>
  21 Signed-off-by: Archit Taneja <architt@codeaurora.org>
  22 ---
  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(-)
  27
  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
  31         } else {
  32                 ops.len = ops.ooblen = 1;
  33         }
  34 -       ops.mode = MTD_OPS_PLACE_OOB;
  35 +
  36 +       if (unlikely(chip->bbt_options & NAND_BBT_ACCESS_BBM_RAW))
  37 +               ops.mode = MTD_OPS_RAW;
  38 +       else
  39 +               ops.mode = MTD_OPS_PLACE_OOB;
  40
  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
  46         ops.oobbuf = buf;
  47         ops.ooboffs = 0;
  48         ops.datbuf = NULL;
  49 -       ops.mode = MTD_OPS_PLACE_OOB;
  50 +
  51 +       if (unlikely(bd->options & NAND_BBT_ACCESS_BBM_RAW))
  52 +               ops.mode = MTD_OPS_RAW;
  53 +       else
  54 +               ops.mode = MTD_OPS_PLACE_OOB;
  55
  56         for (j = 0; j < numpages; j++) {
  57                 /*
  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
  62
  63  /*
  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
  67 + */
  68 +#define NAND_BBT_ACCESS_BBM_RAW        0x00100000
  69 +/*
  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.