max17042_battery: Fix error handling

In max17042_get_property(...), the values returned by
max17042_read_reg are directly assigned to the variables,
even if the read results in an error.

This patch checks for the return code from max17042_read_reg and
exits the function if there is any error.

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

1 files changed, 58 insertions, 27 deletions

diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
index a6dc9c7a95e2..10ffa8c22d36 100644
--- a/drivers/power/max17042_battery.c
+++ b/drivers/power/max17042_battery.c
@@ -84,55 +84,79 @@ static int max17042_get_property(struct power_supply *psy,
 {
         struct max17042_chip *chip = container_of(psy,
                                 struct max17042_chip, battery);
+        int ret;
 
         switch (psp) {
         case POWER_SUPPLY_PROP_PRESENT:
-                val->intval = max17042_read_reg(chip->client,
-                                MAX17042_STATUS);
-                if (val->intval & MAX17042_STATUS_BattAbsent)
+                ret = max17042_read_reg(chip->client, MAX17042_STATUS);
+                if (ret < 0)
+                        return ret;
+
+                if (ret & MAX17042_STATUS_BattAbsent)
                         val->intval = 0;
                 else
                         val->intval = 1;
                 break;
         case POWER_SUPPLY_PROP_CYCLE_COUNT:
-                val->intval = max17042_read_reg(chip->client,
-                                MAX17042_Cycles);
+                ret = max17042_read_reg(chip->client, MAX17042_Cycles);
+                if (ret < 0)
+                        return ret;
+
+                val->intval = ret;
                 break;
         case POWER_SUPPLY_PROP_VOLTAGE_MAX:
-                val->intval = max17042_read_reg(chip->client,
-                                MAX17042_MinMaxVolt);
-                val->intval >>= 8;
+                ret = max17042_read_reg(chip->client, MAX17042_MinMaxVolt);
+                if (ret < 0)
+                        return ret;
+
+                val->intval = ret >> 8;
                 val->intval *= 20000; /* Units of LSB = 20mV */
                 break;
         case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
-                val->intval = max17042_read_reg(chip->client,
-                                MAX17042_V_empty);
-                val->intval >>= 7;
+                ret = max17042_read_reg(chip->client, MAX17042_V_empty);
+                if (ret < 0)
+                        return ret;
+
+                val->intval = ret >> 7;
                 val->intval *= 10000; /* Units of LSB = 10mV */
                 break;
         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
-                val->intval = max17042_read_reg(chip->client, MAX17042_VCELL)
-                            * 625 / 8;
+                ret = max17042_read_reg(chip->client, MAX17042_VCELL);
+                if (ret < 0)
+                        return ret;
+
+                val->intval = ret * 625 / 8;
                 break;
         case POWER_SUPPLY_PROP_VOLTAGE_AVG:
-                val->intval = max17042_read_reg(chip->client, MAX17042_AvgVCELL)
-                            * 625 / 8;
+                ret = max17042_read_reg(chip->client, MAX17042_AvgVCELL);
+                if (ret < 0)
+                        return ret;
+
+                val->intval = ret * 625 / 8;
                 break;
         case POWER_SUPPLY_PROP_CAPACITY:
-                val->intval = max17042_read_reg(chip->client,
-                                MAX17042_SOC) / 256;
+                ret = max17042_read_reg(chip->client, MAX17042_SOC);
+                if (ret < 0)
+                        return ret;
+
+                val->intval = ret >> 8;
                 break;
         case POWER_SUPPLY_PROP_CHARGE_FULL:
-                val->intval = max17042_read_reg(chip->client,
-                                MAX17042_RepSOC);
-                if ((val->intval / 256) >= MAX17042_BATTERY_FULL)
+                ret = max17042_read_reg(chip->client, MAX17042_RepSOC);
+                if (ret < 0)
+                        return ret;
+
+                if ((ret >> 8) >= MAX17042_BATTERY_FULL)
                         val->intval = 1;
-                else if (val->intval >= 0)
+                else if (ret >= 0)
                         val->intval = 0;
                 break;
         case POWER_SUPPLY_PROP_TEMP:
-                val->intval = max17042_read_reg(chip->client,
-                                MAX17042_TEMP);
+                ret = max17042_read_reg(chip->client, MAX17042_TEMP);
+                if (ret < 0)
+                        return ret;
+
+                val->intval = ret;
                 /* The value is signed. */
                 if (val->intval & 0x8000) {
                         val->intval = (0x7fff & ~val->intval) + 1;
@@ -144,8 +168,11 @@ static int max17042_get_property(struct power_supply *psy,
                 break;
         case POWER_SUPPLY_PROP_CURRENT_NOW:
                 if (chip->pdata->enable_current_sense) {
-                        val->intval = max17042_read_reg(chip->client,
-                                        MAX17042_Current);
+                        ret = max17042_read_reg(chip->client, MAX17042_Current);
+                        if (ret < 0)
+                                return ret;
+
+                        val->intval = ret;
                         if (val->intval & 0x8000) {
                                 /* Negative */
                                 val->intval = ~val->intval & 0x7fff;
@@ -159,8 +186,12 @@ static int max17042_get_property(struct power_supply *psy,
                 break;
         case POWER_SUPPLY_PROP_CURRENT_AVG:
                 if (chip->pdata->enable_current_sense) {
-                        val->intval = max17042_read_reg(chip->client,
-                                        MAX17042_AvgCurrent);
+                        ret = max17042_read_reg(chip->client,
+                                                MAX17042_AvgCurrent);
+                        if (ret < 0)
+                                return ret;
+
+                        val->intval = ret;
                         if (val->intval & 0x8000) {
                                 /* Negative */
                                 val->intval = ~val->intval & 0x7fff;