target/linux/generic/patches-4.4/041-mtd-bcm47xxpart-don-t-fail-because-of-bit-flips.patch

   1 From 36bcc0c9c2bc8f56569cd735ba531a51358d7c2b 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 11:31:38 +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 Signed-off-by: Brian Norris <computersforpeace@gmail.com>
  14 ---
  15  drivers/mtd/bcm47xxpart.c | 38 ++++++++++++++++++++++----------------
  16  1 file changed, 22 insertions(+), 16 deletions(-)
  17
  18 --- a/drivers/mtd/bcm47xxpart.c
  19 +++ b/drivers/mtd/bcm47xxpart.c
  20 @@ -66,11 +66,13 @@ static const char *bcm47xxpart_trx_data_
  21  {
  22         uint32_t buf;
  23         size_t bytes_read;
  24 +       int err;
  25
  26 -       if (mtd_read(master, offset, sizeof(buf), &bytes_read,
  27 -                    (uint8_t *)&buf) < 0) {
  28 -               pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
  29 -                       offset);
  30 +       err  = mtd_read(master, offset, sizeof(buf), &bytes_read,
  31 +                       (uint8_t *)&buf);
  32 +       if (err && !mtd_is_bitflip(err)) {
  33 +               pr_err("mtd_read error while parsing (offset: 0x%X): %d\n",
  34 +                       offset, err);
  35                 goto out_default;
  36         }
  37
  38 @@ -95,6 +97,7 @@ static int bcm47xxpart_parse(struct mtd_
  39         int trx_part = -1;
  40         int last_trx_part = -1;
  41         int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, };
  42 +       int err;
  43
  44         /*
  45          * Some really old flashes (like AT45DB*) had smaller erasesize-s, but
  46 @@ -128,10 +131,11 @@ static int bcm47xxpart_parse(struct mtd_
  47                 }
  48
  49                 /* Read beginning of the block */
  50 -               if (mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ,
  51 -                            &bytes_read, (uint8_t *)buf) < 0) {
  52 -                       pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
  53 -                              offset);
  54 +               err = mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ,
  55 +                              &bytes_read, (uint8_t *)buf);
  56 +               if (err && !mtd_is_bitflip(err)) {
  57 +                       pr_err("mtd_read error while parsing (offset: 0x%X): %d\n",
  58 +                              offset, err);
  59                         continue;
  60                 }
  61
  62 @@ -254,10 +258,11 @@ static int bcm47xxpart_parse(struct mtd_
  63                 }
  64
  65                 /* Read middle of the block */
  66 -               if (mtd_read(master, offset + 0x8000, 0x4,
  67 -                            &bytes_read, (uint8_t *)buf) < 0) {
  68 -                       pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
  69 -                              offset);
  70 +               err = mtd_read(master, offset + 0x8000, 0x4, &bytes_read,
  71 +                              (uint8_t *)buf);
  72 +               if (err && !mtd_is_bitflip(err)) {
  73 +                       pr_err("mtd_read error while parsing (offset: 0x%X): %d\n",
  74 +                              offset, err);
  75                         continue;
  76                 }
  77
  78 @@ -277,10 +282,11 @@ static int bcm47xxpart_parse(struct mtd_
  79                 }
  80
  81                 offset = master->size - possible_nvram_sizes[i];
  82 -               if (mtd_read(master, offset, 0x4, &bytes_read,
  83 -                            (uint8_t *)buf) < 0) {
  84 -                       pr_err("mtd_read error while reading at offset 0x%X!\n",
  85 -                              offset);
  86 +               err = mtd_read(master, offset, 0x4, &bytes_read,
  87 +                              (uint8_t *)buf);
  88 +               if (err && !mtd_is_bitflip(err)) {
  89 +                       pr_err("mtd_read error while reading (offset 0x%X): %d\n",
  90 +                              offset, err);
  91                         continue;
  92                 }
  93