[PATCH] iio: adc: imx25-gcq: fix uninitialized variable usage

[Yizhuo]

In function mx25_gcq_irq(), local variable "stats" could
be uninitialized if function regmap_read() returns -EINVAL.
However, this value is used in if statement, which is
potentially unsafe. The same case applied to the variable
"data" in function mx25_gcq_get_raw_value() in the same file.

Signed-off-by: Yizhuo <yzhai...@ucr.edu>
---
 drivers/iio/adc/fsl-imx25-gcq.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/fsl-imx25-gcq.c b/drivers/iio/adc/fsl-imx25-gcq.c
index fa71489195c6..3b1e12b7c1ac 100644
--- a/drivers/iio/adc/fsl-imx25-gcq.c
+++ b/drivers/iio/adc/fsl-imx25-gcq.c
@@ -73,8 +73,12 @@ static irqreturn_t mx25_gcq_irq(int irq, void *data)
 {
        struct mx25_gcq_priv *priv = data;
        u32 stats;
+       int ret;
 
-       regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
+       ret = regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
+       if (ret) {
+               return ret;
+       }
 
        if (stats & MX25_ADCQ_SR_EOQ) {
                regmap_update_bits(priv->regs, MX25_ADCQ_MR,
@@ -100,6 +104,7 @@ static int mx25_gcq_get_raw_value(struct device *dev,
 {
        long timeout;
        u32 data;
+       int ret;
 
        /* Setup the configuration we want to use */
        regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
@@ -121,7 +126,11 @@ static int mx25_gcq_get_raw_value(struct device *dev,
                return -ETIMEDOUT;
        }
 
-       regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
+       ret = regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
+       if (ret) {
+               dev_err(dev, "Failed to read MX25_ADCQ_FIFO.\n");
+               return ret;
+       }
 
        *val = MX25_ADCQ_FIFO_DATA(data);
 
-- 
2.17.1