target/linux/generic/pending-4.14/412-mtd-partial_eraseblock_unlock.patch

   1 From: Tim Harvey <tharvey@gateworks.com>
   2 Subject: mtd: allow partial block unlock
   3
   4 This allows sysupgrade for devices such as the Gateworks Avila/Cambria
   5 product families based on the ixp4xx using the redboot bootloader with
   6 combined FIS directory and RedBoot config partitions on larger FLASH
   7 devices with larger eraseblocks.
   8
   9 This second iteration of this patch addresses previous issues:
  10 - whitespace breakage fixed
  11 - unlock in all scenarios
  12 - simplification and fix logic bug
  13
  14 [john@phrozen.org: this should be moved to the ixp4xx folder]
  15
  16 Signed-off-by: Tim Harvey <tharvey@gateworks.com>
  17 ---
  18  drivers/mtd/mtdpart.c | 11 ++++++++++-
  19  1 file changed, 10 insertions(+), 1 deletion(-)
  20
  21 --- a/drivers/mtd/mtdpart.c
  22 +++ b/drivers/mtd/mtdpart.c
  23 @@ -348,7 +348,16 @@ static int part_lock(struct mtd_info *mt
  24  static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
  25  {
  26         struct mtd_part *part = mtd_to_part(mtd);
  27 -       return part->parent->_unlock(part->parent, ofs + part->offset, len);
  28 +
  29 +       ofs += part->offset;
  30 +
  31 +       if (mtd->flags & MTD_ERASE_PARTIAL) {
  32 +               /* round up len to next erasesize and round down offset to prev block */
  33 +               len = (mtd_div_by_eb(len, part->parent) + 1) * part->parent->erasesize;
  34 +               ofs &= ~(part->parent->erasesize - 1);
  35 +       }
  36 +
  37 +       return part->parent->_unlock(part->parent, ofs, len);
  38  }
  39
  40  static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)