target/linux/generic/patches-4.9/490-ubi-auto-attach-mtd-device-named-ubi-or-data-on-boot.patch

   1 From 8a52e4100d7c3a4a1dfddfa02b8864a9b0068c13 Mon Sep 17 00:00:00 2001
   2 From: Daniel Golle <daniel@makrotopia.org>
   3 Date: Sat, 17 May 2014 03:36:18 +0200
   4 Subject: [PATCH 1/5] ubi: auto-attach mtd device named "ubi" or "data" on boot
   5 To: openwrt-devel@lists.openwrt.org
   6
   7 Signed-off-by: Daniel Golle <daniel@makrotopia.org>
   8 ---
   9  drivers/mtd/ubi/build.c | 36 ++++++++++++++++++++++++++++++++++++
  10  1 file changed, 36 insertions(+)
  11
  12 Index: linux-4.9.17/drivers/mtd/ubi/build.c
  13 ===================================================================
  14 --- linux-4.9.17.orig/drivers/mtd/ubi/build.c
  15 +++ linux-4.9.17/drivers/mtd/ubi/build.c
  16 @@ -1212,6 +1212,49 @@ static struct mtd_info * __init open_mtd
  17         return mtd;
  18  }
  19
  20 +/*
  21 + * This function tries attaching mtd partitions named either "ubi" or "data"
  22 + * during boot.
  23 + */
  24 +static void __init ubi_auto_attach(void)
  25 +{
  26 +       int err;
  27 +       struct mtd_info *mtd;
  28 +
  29 +       /* try attaching mtd device named "ubi" or "data" */
  30 +       mtd = open_mtd_device("ubi");
  31 +       if (IS_ERR(mtd))
  32 +               mtd = open_mtd_device("data");
  33 +
  34 +       if (!IS_ERR(mtd)) {
  35 +               size_t len;
  36 +               char magic[4];
  37 +
  38 +               /* check for a valid ubi magic */
  39 +               err = mtd_read(mtd, 0, 4, &len, (void *) magic);
  40 +               if (!err && len == 4 && strncmp(magic, "UBI#", 4)) {
  41 +                       pr_err("UBI error: no valid UBI magic found inside mtd%d", mtd->index);
  42 +                       put_mtd_device(mtd);
  43 +                       return;
  44 +               }
  45 +
  46 +               /* auto-add only media types where UBI makes sense */
  47 +               if (mtd->type == MTD_NANDFLASH ||
  48 +                   mtd->type == MTD_NORFLASH ||
  49 +                   mtd->type == MTD_DATAFLASH ||
  50 +                   mtd->type == MTD_MLCNANDFLASH) {
  51 +                       mutex_lock(&ubi_devices_mutex);
  52 +                       pr_notice("UBI: auto-attach mtd%d\n", mtd->index);
  53 +                       err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO, 0, 0);
  54 +                       mutex_unlock(&ubi_devices_mutex);
  55 +                       if (err < 0) {
  56 +                               pr_err("UBI error: cannot attach mtd%d", mtd->index);
  57 +                               put_mtd_device(mtd);
  58 +                       }
  59 +               }
  60 +       }
  61 +}
  62 +
  63  static int __init ubi_init(void)
  64  {
  65         int err, i, k;
  66 @@ -1295,6 +1338,12 @@ static int __init ubi_init(void)
  67                 }
  68         }
  69
  70 +       /* auto-attach mtd devices only if built-in to the kernel and no ubi.mtd
  71 +        * parameter was given */
  72 +       if (IS_ENABLED(CONFIG_MTD_ROOTFS_ROOT_DEV) &&
  73 +           !ubi_is_module() && !mtd_devs)
  74 +               ubi_auto_attach();
  75 +
  76         err = ubiblock_init();
  77         if (err) {
  78                 pr_err("UBI error: block: cannot initialize, error %d", err);