From 7e1da86339f29e445e40d41132c30741df8c19ad Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 25 Jan 2016 16:52:40 +0100 Subject: [PATCH] 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 Signed-off-by: Jonathan Cameron --- drivers/staging/iio/meter/ade7753.c | 12 ++++++++++-- 1 file 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); -- 2.34.1