queue-4.9/iio-common-ssp_sensors-initialize-calculated_time-in.patch

   1 From db1da1d38f04a1fd7a8a10c25bd8e96377332d25 Mon Sep 17 00:00:00 2001
   2 From: Nathan Chancellor <natechancellor@gmail.com>
   3 Date: Thu, 7 Mar 2019 14:45:46 -0700
   4 Subject: iio: common: ssp_sensors: Initialize calculated_time in
   5  ssp_common_process_data
   6
   7 [ Upstream commit 6f9ca1d3eb74b81f811a87002de2d51640d135b1 ]
   8
   9 When building with -Wsometimes-uninitialized, Clang warns:
  10
  11 drivers/iio/common/ssp_sensors/ssp_iio.c:95:6: warning: variable
  12 'calculated_time' is used uninitialized whenever 'if' condition is false
  13 [-Wsometimes-uninitialized]
  14
  15 While it isn't wrong, this will never be a problem because
  16 iio_push_to_buffers_with_timestamp only uses calculated_time
  17 on the same condition that it is assigned (when scan_timestamp
  18 is not zero). While iio_push_to_buffers_with_timestamp is marked
  19 as inline, Clang does inlining in the optimization stage, which
  20 happens after the semantic analysis phase (plus inline is merely
  21 a hint to the compiler).
  22
  23 Fix this by just zero initializing calculated_time.
  24
  25 Link: https://github.com/ClangBuiltLinux/linux/issues/394
  26 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
  27 Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
  28 Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
  29 Signed-off-by: Sasha Levin <sashal@kernel.org>
  30 ---
  31  drivers/iio/common/ssp_sensors/ssp_iio.c | 2 +-
  32  1 file changed, 1 insertion(+), 1 deletion(-)
  33
  34 diff --git a/drivers/iio/common/ssp_sensors/ssp_iio.c b/drivers/iio/common/ssp_sensors/ssp_iio.c
  35 index a3ae165f8d9f3..16180e6321bd4 100644
  36 --- a/drivers/iio/common/ssp_sensors/ssp_iio.c
  37 +++ b/drivers/iio/common/ssp_sensors/ssp_iio.c
  38 @@ -80,7 +80,7 @@ int ssp_common_process_data(struct iio_dev *indio_dev, void *buf,
  39                             unsigned int len, int64_t timestamp)
  40  {
  41         __le32 time;
  42 -       int64_t calculated_time;
  43 +       int64_t calculated_time = 0;
  44         struct ssp_sensor_data *spd = iio_priv(indio_dev);
  45
  46         if (indio_dev->scan_bytes == 0)
  47 --
  48 2.20.1
  49