thermal: qcom: Fix comparison with uninitialized variable channels_available

Currently the check of chip->channels[i].channel is against an the
uninitialized variable channels_available.  I believe the variable
channels_available needs to be fetched first by the call to adc_tm5_read
before the channels check. Fix the issue swapping the order of the
channels check loop with the call to adc_tm5_read.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: ca66dca5eda6 ("thermal: qcom: add support for adc-tm5 PMIC thermal monitor")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210216151626.162996-1-colin.king@canonical.com

diff --git a/drivers/thermal/qcom/qcom-spmi-adc-tm5.c b/drivers/thermal/qcom/qcom-spmi-adc-tm5.c
index a201437..b460b56 100644 (file)
--- a/drivers/thermal/qcom/qcom-spmi-adc-tm5.c
+++ b/drivers/thermal/qcom/qcom-spmi-adc-tm5.c
@@ -375,13 +375,6 @@ static int adc_tm5_init(struct adc_tm5_chip *chip)
        int ret;
        unsigned int i;
 
-       for (i = 0; i < chip->nchannels; i++) {
-               if (chip->channels[i].channel >= channels_available) {
-                       dev_err(chip->dev, "Invalid channel %d\n", chip->channels[i].channel);
-                       return -EINVAL;
-               }
-       }
-
        ret = adc_tm5_read(chip, ADC_TM5_NUM_BTM,
                           &channels_available, sizeof(channels_available));
        if (ret) {
@@ -389,6 +382,13 @@ static int adc_tm5_init(struct adc_tm5_chip *chip)
                return ret;
        }
 
+       for (i = 0; i < chip->nchannels; i++) {
+               if (chip->channels[i].channel >= channels_available) {
+                       dev_err(chip->dev, "Invalid channel %d\n", chip->channels[i].channel);
+                       return -EINVAL;
+               }
+       }
+
        buf[0] = chip->decimation;
        buf[1] = chip->avg_samples | ADC_TM5_FAST_AVG_EN;
        buf[2] = ADC_TM5_TIMER1;