iio: ade7753: avoid uninitialized data
authorArnd Bergmann <arnd@arndb.de>
Mon, 25 Jan 2016 15:52:40 +0000 (16:52 +0100)
committerJonathan Cameron <jic23@kernel.org>
Sat, 30 Jan 2016 16:24:24 +0000 (16:24 +0000)
commit7e1da86339f29e445e40d41132c30741df8c19ad
tree55ec842855bdbb7245fc9fc36080b9c63fd26b87
parent431386e783a3a6c8b7707bee32d18c353b8688b2
iio: ade7753: avoid uninitialized data

The ade7753_spi_read_reg_16() will either successfully read a value
from SPI, or return a failure code without delivering data. However,
the ade7753_stop_device() and ade7753_reset() functions use the returned
data without checking for an error condition first. Gcc detects this
as a possible bug and warns about it:

drivers/staging/iio/meter/ade7753.c: In function 'ade7753_remove':
drivers/staging/iio/meter/ade7753.c:348:6: error: 'val' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  val |= BIT(4);  /* AD converters can be turned off */
      ^
drivers/staging/iio/meter/ade7753.c:345:6: note: 'val' was declared here
  u16 val;
      ^
drivers/staging/iio/meter/ade7753.c: In function 'ade7753_probe':
drivers/staging/iio/meter/ade7753.c:222:6: error: 'val' may be used uninitialized in this function [-Werror=maybe-uninitialized]

In both cases, we can avoids the warning by checking the return code
before using the data.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
drivers/staging/iio/meter/ade7753.c