target/linux/lantiq/patches-3.18/0015-MTD-lantiq-xway-remove-endless-loop.patch

   1 From 76e153079f02d26e3357302d2886a0c8aaaec64d Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Sun, 28 Jul 2013 18:02:06 +0200
   4 Subject: [PATCH 15/36] MTD: lantiq: xway: remove endless loop
   5
   6 The reset loop logic could run into a endless loop. Lets fix it as requested.
   7
   8 --> http://lists.infradead.org/pipermail/linux-mtd/2012-September/044240.html
   9
  10 Signed-off-by: John Crispin <blogic@openwrt.org>
  11 ---
  12  drivers/mtd/nand/xway_nand.c |   10 ++++++++--
  13  1 file changed, 8 insertions(+), 2 deletions(-)
  14
  15 --- a/drivers/mtd/nand/xway_nand.c
  16 +++ b/drivers/mtd/nand/xway_nand.c
  17 @@ -59,16 +59,22 @@ static u32 xway_latchcmd;
  18  static void xway_reset_chip(struct nand_chip *chip)
  19  {
  20         unsigned long nandaddr = (unsigned long) chip->IO_ADDR_W;
  21 +       unsigned long timeout;
  22         unsigned long flags;
  23
  24         nandaddr &= ~NAND_WRITE_ADDR;
  25         nandaddr |= NAND_WRITE_CMD;
  26
  27         /* finish with a reset */
  28 +       timeout = jiffies + msecs_to_jiffies(20);
  29 +
  30         spin_lock_irqsave(&ebu_lock, flags);
  31         writeb(NAND_WRITE_CMD_RESET, (void __iomem *) nandaddr);
  32 -       while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
  33 -               ;
  34 +       do {
  35 +               if ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
  36 +                       break;
  37 +               cond_resched();
  38 +       } while (!time_after_eq(jiffies, timeout));
  39         spin_unlock_irqrestore(&ebu_lock, flags);
  40  }
  41