target/linux/generic/patches-4.4/144-mtd-bcm47xxpart-don-t-fail-because-of-bit-flips.patch

   1 From dfe4b4c732365fc1d83c2d2fd9cc18054ae850b7 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
   3 Date: Sun, 6 Dec 2015 11:24:05 +0100
   4 Subject: [PATCH] mtd: bcm47xxpart: don't fail because of bit-flips
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Bit-flip errors may occur on NAND flashes and are harmless. Handle them
  10 gracefully as read content is still reliable and can be parsed.
  11
  12 Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
  13 ---
  14  drivers/mtd/bcm47xxpart.c | 38 ++++++++++++++++++++++----------------
  15  1 file changed, 22 insertions(+), 16 deletions(-)
  16
  17 --- a/drivers/mtd/bcm47xxpart.c
  18 +++ b/drivers/mtd/bcm47xxpart.c
  19 @@ -66,11 +66,13 @@ static const char *bcm47xxpart_trx_data_
  20  {
  21         uint32_t buf;
  22         size_t bytes_read;
  23 +       int err;
  24
  25 -       if (mtd_read(master, offset, sizeof(buf), &bytes_read,
  26 -                    (uint8_t *)&buf) < 0) {
  27 -               pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
  28 -                       offset);
  29 +       err  = mtd_read(master, offset, sizeof(buf), &bytes_read,
  30 +                       (uint8_t *)&buf);
  31 +       if (err && !mtd_is_bitflip(err)) {
  32 +               pr_err("mtd_read error while parsing (offset: 0x%X): %d\n",
  33 +                       offset, err);
  34                 goto out_default;
  35         }
  36
  37 @@ -95,6 +97,7 @@ static int bcm47xxpart_parse(struct mtd_
  38         int trx_part = -1;
  39         int last_trx_part = -1;
  40         int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, };
  41 +       int err;
  42
  43         /*
  44          * Some really old flashes (like AT45DB*) had smaller erasesize-s, but
  45 @@ -128,10 +131,11 @@ static int bcm47xxpart_parse(struct mtd_
  46                 }
  47
  48                 /* Read beginning of the block */
  49 -               if (mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ,
  50 -                            &bytes_read, (uint8_t *)buf) < 0) {
  51 -                       pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
  52 -                              offset);
  53 +               err = mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ,
  54 +                              &bytes_read, (uint8_t *)buf);
  55 +               if (err && !mtd_is_bitflip(err)) {
  56 +                       pr_err("mtd_read error while parsing (offset: 0x%X): %d\n",
  57 +                              offset, err);
  58                         continue;
  59                 }
  60
  61 @@ -254,10 +258,11 @@ static int bcm47xxpart_parse(struct mtd_
  62                 }
  63
  64                 /* Read middle of the block */
  65 -               if (mtd_read(master, offset + 0x8000, 0x4,
  66 -                            &bytes_read, (uint8_t *)buf) < 0) {
  67 -                       pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
  68 -                              offset);
  69 +               err = mtd_read(master, offset + 0x8000, 0x4, &bytes_read,
  70 +                              (uint8_t *)buf);
  71 +               if (err && !mtd_is_bitflip(err)) {
  72 +                       pr_err("mtd_read error while parsing (offset: 0x%X): %d\n",
  73 +                              offset, err);
  74                         continue;
  75                 }
  76
  77 @@ -277,10 +282,11 @@ static int bcm47xxpart_parse(struct mtd_
  78                 }
  79
  80                 offset = master->size - possible_nvram_sizes[i];
  81 -               if (mtd_read(master, offset, 0x4, &bytes_read,
  82 -                            (uint8_t *)buf) < 0) {
  83 -                       pr_err("mtd_read error while reading at offset 0x%X!\n",
  84 -                              offset);
  85 +               err = mtd_read(master, offset, 0x4, &bytes_read,
  86 +                              (uint8_t *)buf);
  87 +               if (err && !mtd_is_bitflip(err)) {
  88 +                       pr_err("mtd_read error while reading (offset 0x%X): %d\n",
  89 +                              offset, err);
  90                         continue;
  91                 }
  92