UBI: fix NOR flash recovery

This commit fixes NOR flash recovery issues observed with Spansion
S29GL512N NOR.

When NOR erases, it first fills PEBs with zeroes, then sets all bytes
to 0xFF. Filling with zeroes starts from the end of the PEB. And when
power is cut, this results in PEBs containing correct EC and VID headers
but corrupted with zeros at the end. This confuses UBI and it mistakinly
accepts these PEBs and associate them with LEBs.

Fis this issue by zeroing EC and VID magics before erasing PEBs, to
make UBI later refuse zem.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 64604e8809ec..6a5fe9633783 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -373,6 +373,7 @@ struct ubi_wl_entry;
  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
  *               not
+ * @nor_flash: non-zero if working on top of NOR flash
  * @mtd: MTD device descriptor
  *
  * @peb_buf1: a buffer of PEB size used for different purposes
@@ -454,7 +455,8 @@ struct ubi_device {
         int vid_hdr_offset;
         int vid_hdr_aloffset;
         int vid_hdr_shift;
-        int bad_allowed;
+        unsigned int bad_allowed:1;
+        unsigned int nor_flash:1;
         struct mtd_info *mtd;
 
         void *peb_buf1;