queue-4.4/mfd-ab8500-core-return-zero-in-get_register_interrup.patch

   1 From 7da38c2f4131e2951c099ea476e498b887101647 Mon Sep 17 00:00:00 2001
   2 From: Dan Carpenter <dan.carpenter@oracle.com>
   3 Date: Thu, 25 Oct 2018 15:43:44 +0300
   4 Subject: mfd: ab8500-core: Return zero in get_register_interruptible()
   5
   6 [ Upstream commit 10628e3ecf544fa2e4e24f8e112d95c37884dc98 ]
   7
   8 This function is supposed to return zero on success or negative error
   9 codes on error.  Unfortunately, there is a bug so it sometimes returns
  10 non-zero, positive numbers on success.
  11
  12 I noticed this bug during review and I can't test it.  It does appear
  13 that the return is sometimes propogated back to _regmap_read() where all
  14 non-zero returns are treated as failure so this may affect run time.
  15
  16 Fixes: 47c1697508f2 ("mfd: Align ab8500 with the abx500 interface")
  17 Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
  18 Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
  19 Signed-off-by: Lee Jones <lee.jones@linaro.org>
  20 Signed-off-by: Sasha Levin <sashal@kernel.org>
  21 ---
  22  drivers/mfd/ab8500-core.c | 2 +-
  23  1 file changed, 1 insertion(+), 1 deletion(-)
  24
  25 diff --git a/drivers/mfd/ab8500-core.c b/drivers/mfd/ab8500-core.c
  26 index fefbe4cfa61dd..1263cfd8b4d2f 100644
  27 --- a/drivers/mfd/ab8500-core.c
  28 +++ b/drivers/mfd/ab8500-core.c
  29 @@ -259,7 +259,7 @@ static int get_register_interruptible(struct ab8500 *ab8500, u8 bank,
  30         mutex_unlock(&ab8500->lock);
  31         dev_vdbg(ab8500->dev, "rd: addr %#x => data %#x\n", addr, ret);
  32
  33 -       return ret;
  34 +       return (ret < 0) ? ret : 0;
  35  }
  36
  37  static int ab8500_get_register(struct device *dev, u8 bank,
  38 --
  39 2.19.1
  40