target/linux/generic/pending-5.4/481-mtd-spi-nor-rework-broken-flash-reset-support.patch

   1 From ea92cbb50a78404e29de2cc3999a240615ffb1c8 Mon Sep 17 00:00:00 2001
   2 From: Chuanhong Guo <gch981213@gmail.com>
   3 Date: Mon, 6 Apr 2020 17:58:48 +0800
   4 Subject: [PATCH] mtd: spi-nor: rework broken-flash-reset support
   5
   6 Instead of resetting flash to 3B address on remove hook, this
   7 implementation only enters 4B mode when needed, which prevents
   8 more unexpected reboot stuck. This implementation makes it only
   9 break when a kernel panic happens during flash operation on 16M+
  10 areas.
  11 *OpenWrt only*: silent broken-flash-reset warning. We are not dealing
  12 with vendors and it's unpleasant for users to se that unnecessary
  13 and long WARN_ON print.
  14
  15 Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
  16 ---
  17  drivers/mtd/spi-nor/spi-nor.c | 52 +++++++++++++++++++++++++++++++++--
  18  1 file changed, 49 insertions(+), 3 deletions(-)
  19
  20 --- a/drivers/mtd/spi-nor/spi-nor.c
  21 +++ b/drivers/mtd/spi-nor/spi-nor.c
  22 @@ -616,6 +616,22 @@ static void spi_nor_set_4byte_opcodes(st
  23         }
  24  }
  25
  26 +static int spi_nor_check_set_addr_width(struct spi_nor *nor, loff_t addr)
  27 +{
  28 +       u8 addr_width;
  29 +
  30 +       if ((nor->flags & (SNOR_F_4B_OPCODES | SNOR_F_BROKEN_RESET)) !=
  31 +           SNOR_F_BROKEN_RESET)
  32 +               return 0;
  33 +
  34 +       addr_width = addr & 0xff000000 ? 4 : 3;
  35 +       if (nor->addr_width == addr_width)
  36 +               return 0;
  37 +
  38 +       nor->addr_width = addr_width;
  39 +       return nor->params.set_4byte(nor, addr_width == 4);
  40 +}
  41 +
  42  static int macronix_set_4byte(struct spi_nor *nor, bool enable)
  43  {
  44         if (nor->spimem) {
  45 @@ -1259,6 +1275,10 @@ static int spi_nor_erase(struct mtd_info
  46         if (ret)
  47                 return ret;
  48
  49 +       ret = spi_nor_check_set_addr_width(nor, instr->addr + instr->len);
  50 +       if (ret < 0)
  51 +               return ret;
  52 +
  53         /* whole-chip erase? */
  54         if (len == mtd->size && !(nor->flags & SNOR_F_NO_OP_CHIP_ERASE)) {
  55                 unsigned long timeout;
  56 @@ -1315,6 +1335,7 @@ static int spi_nor_erase(struct mtd_info
  57         write_disable(nor);
  58
  59  erase_err:
  60 +       spi_nor_check_set_addr_width(nor, 0);
  61         spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_ERASE);
  62
  63         return ret;
  64 @@ -1621,7 +1642,9 @@ static int spi_nor_lock(struct mtd_info
  65         if (ret)
  66                 return ret;
  67
  68 +       spi_nor_check_set_addr_width(nor, ofs + len);
  69         ret = nor->params.locking_ops->lock(nor, ofs, len);
  70 +       spi_nor_check_set_addr_width(nor, 0);
  71
  72         spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_UNLOCK);
  73         return ret;
  74 @@ -1636,7 +1659,9 @@ static int spi_nor_unlock(struct mtd_inf
  75         if (ret)
  76                 return ret;
  77
  78 +       spi_nor_check_set_addr_width(nor, ofs + len);
  79         ret = nor->params.locking_ops->unlock(nor, ofs, len);
  80 +       spi_nor_check_set_addr_width(nor, 0);
  81
  82         spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
  83         return ret;
  84 @@ -1651,7 +1676,9 @@ static int spi_nor_is_locked(struct mtd_
  85         if (ret)
  86                 return ret;
  87
  88 +       spi_nor_check_set_addr_width(nor, ofs + len);
  89         ret = nor->params.locking_ops->is_locked(nor, ofs, len);
  90 +       spi_nor_check_set_addr_width(nor, 0);
  91
  92         spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
  93         return ret;
  94 @@ -2557,6 +2584,10 @@ static int spi_nor_read(struct mtd_info
  95         if (ret)
  96                 return ret;
  97
  98 +       ret = spi_nor_check_set_addr_width(nor, from + len);
  99 +       if (ret < 0)
 100 +               return ret;
 101 +
 102         while (len) {
 103                 loff_t addr = from;
 104
 105 @@ -2580,6 +2611,7 @@ static int spi_nor_read(struct mtd_info
 106         ret = 0;
 107
 108  read_err:
 109 +       spi_nor_check_set_addr_width(nor, 0);
 110         spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ);
 111         return ret;
 112  }
 113 @@ -2597,6 +2629,10 @@ static int sst_write(struct mtd_info *mt
 114         if (ret)
 115                 return ret;
 116
 117 +       ret = spi_nor_check_set_addr_width(nor, to + len);
 118 +       if (ret < 0)
 119 +               return ret;
 120 +
 121         write_enable(nor);
 122
 123         nor->sst_write_second = false;
 124 @@ -2659,6 +2695,7 @@ static int sst_write(struct mtd_info *mt
 125         }
 126  sst_write_err:
 127         *retlen += actual;
 128 +       spi_nor_check_set_addr_width(nor, 0);
 129         spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE);
 130         return ret;
 131  }
 132 @@ -2681,6 +2718,10 @@ static int spi_nor_write(struct mtd_info
 133         if (ret)
 134                 return ret;
 135
 136 +       ret = spi_nor_check_set_addr_width(nor, to + len);
 137 +       if (ret < 0)
 138 +               return ret;
 139 +
 140         for (i = 0; i < len; ) {
 141                 ssize_t written;
 142                 loff_t addr = to + i;
 143 @@ -2720,6 +2761,7 @@ static int spi_nor_write(struct mtd_info
 144         }
 145
 146  write_err:
 147 +       spi_nor_check_set_addr_width(nor, 0);
 148         spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE);
 149         return ret;
 150  }
 151 @@ -4725,9 +4767,13 @@ static int spi_nor_init(struct spi_nor *
 152                  * reboots (e.g., crashes). Warn the user (or hopefully, system
 153                  * designer) that this is bad.
 154                  */
 155 -               WARN_ONCE(nor->flags & SNOR_F_BROKEN_RESET,
 156 -                         "enabling reset hack; may not recover from unexpected reboots\n");
 157 -               nor->params.set_4byte(nor, true);
 158 +               if (nor->flags & SNOR_F_BROKEN_RESET) {
 159 +                       dev_warn(nor->dev,
 160 +                               "enabling reset hack; may not recover from unexpected reboots\n");
 161 +                       nor->addr_width = 3;
 162 +               } else {
 163 +                       nor->params.set_4byte(nor, true);
 164 +               }
 165         }
 166
 167         return 0;