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| author |   Arnd Bergmann <arnd@arndb.de> | 2016-01-25 16:52:40 +0100 |
|---|---|---|
| committer |   Jonathan Cameron <jic23@kernel.org> | 2016-01-30 16:24:24 +0000 |
| commit | 7e1da86339f29e445e40d41132c30741df8c19ad (patch) | |
| tree | 55ec842855bdbb7245fc9fc36080b9c63fd26b87 /drivers/staging | |
| parent | iio: pressure: mpl115: fix temperature offset sign (diff) | |
| download | linux-dev-7e1da86339f29e445e40d41132c30741df8c19ad.tar.xz linux-dev-7e1da86339f29e445e40d41132c30741df8c19ad.zip | |
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>
Diffstat (limited to 'drivers/staging')
| -rw-r--r-- | drivers/staging/iio/meter/ade7753.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/staging/iio/meter/ade7753.c b/drivers/staging/iio/meter/ade7753.c index f129039bece3..69287108f793 100644 --- a/drivers/staging/iio/meter/ade7753.c +++ b/drivers/staging/iio/meter/ade7753.c @@ -217,8 +217,12 @@ error_ret: static int ade7753_reset(struct device *dev) { u16 val; + int ret; + + ret = ade7753_spi_read_reg_16(dev, ADE7753_MODE, &val); + if (ret) + return ret; - ade7753_spi_read_reg_16(dev, ADE7753_MODE, &val); val |= BIT(6); /* Software Chip Reset */ return ade7753_spi_write_reg_16(dev, ADE7753_MODE, val); @@ -343,8 +347,12 @@ error_ret: static int ade7753_stop_device(struct device *dev) { u16 val; + int ret; + + ret = ade7753_spi_read_reg_16(dev, ADE7753_MODE, &val); + if (ret) + return ret; - ade7753_spi_read_reg_16(dev, ADE7753_MODE, &val); val |= BIT(4); /* AD converters can be turned off */ return ade7753_spi_write_reg_16(dev, ADE7753_MODE, val); |