target/linux/layerscape/patches-4.4/1096-mtd-spi-nor-add-read-loop.patch

   1 From b5929f91416d64afacf46c649f38cc8f0eea50d2 Mon Sep 17 00:00:00 2001
   2 From: Michal Suchanek <hramrach@gmail.com>
   3 Date: Wed, 2 Dec 2015 10:38:20 +0000
   4 Subject: [PATCH 096/113] mtd: spi-nor: add read loop
   5
   6 mtdblock and ubi do not handle the situation when read returns less data
   7 than requested. Loop in spi-nor until buffer is filled or an error is
   8 returned.
   9
  10 Signed-off-by: Michal Suchanek <hramrach@gmail.com>
  11 Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@freescale.com>
  12 ---
  13  drivers/mtd/spi-nor/spi-nor.c |   20 ++++++++++++++------
  14  1 file changed, 14 insertions(+), 6 deletions(-)
  15
  16 --- a/drivers/mtd/spi-nor/spi-nor.c
  17 +++ b/drivers/mtd/spi-nor/spi-nor.c
  18 @@ -921,14 +921,22 @@ static int spi_nor_read(struct mtd_info
  19         if (ret)
  20                 return ret;
  21
  22 -       ret = nor->read(nor, from, len, buf);
  23 +       while (len) {
  24 +               ret = nor->read(nor, from, len, buf);
  25 +               if (ret <= 0)
  26 +                       goto read_err;
  27
  28 -       spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ);
  29 -       if (ret < 0)
  30 -               return ret;
  31 +               WARN_ON(ret > len);
  32 +               *retlen += ret;
  33 +               buf += ret;
  34 +               from += ret;
  35 +               len -= ret;
  36 +       }
  37 +       ret = 0;
  38
  39 -       *retlen += ret;
  40 -       return 0;
  41 +read_err:
  42 +       spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ);
  43 +       return ret;
  44  }
  45
  46  static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,