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authorKangjie Lu <kjlu@umn.edu>2018-12-21 13:01:33 -0600
committerGuenter Roeck <linux@roeck-us.net>2018-12-21 15:37:56 -0800
commitc9c63915519b1def7043b184680f33c24cd49d7b (patch)
tree893bd90f11a1ca968c1b73e86e410fbb1e2237b5
parentf9facc24a6441d6a82d6cca942b162a394ecba66 (diff)
downloadblackbird-obmc-linux-c9c63915519b1def7043b184680f33c24cd49d7b.tar.gz
blackbird-obmc-linux-c9c63915519b1def7043b184680f33c24cd49d7b.zip
hwmon: (lm80) fix a missing check of the status of SMBus read
If lm80_read_value() fails, it returns a negative number instead of the correct read data. Therefore, we should avoid using the data if it fails. The fix checks if lm80_read_value() fails, and if so, returns with the error number. Signed-off-by: Kangjie Lu <kjlu@umn.edu> [groeck: One variable for return values is enough] Signed-off-by: Guenter Roeck <linux@roeck-us.net>
-rw-r--r--drivers/hwmon/lm80.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/hwmon/lm80.c b/drivers/hwmon/lm80.c
index 08e3945a6fbf..04f9df0d2341 100644
--- a/drivers/hwmon/lm80.c
+++ b/drivers/hwmon/lm80.c
@@ -360,9 +360,11 @@ static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
struct i2c_client *client = data->client;
unsigned long min, val;
u8 reg;
- int err = kstrtoul(buf, 10, &val);
- if (err < 0)
- return err;
+ int rv;
+
+ rv = kstrtoul(buf, 10, &val);
+ if (rv < 0)
+ return rv;
/* Save fan_min */
mutex_lock(&data->update_lock);
@@ -390,8 +392,11 @@ static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
return -EINVAL;
}
- reg = (lm80_read_value(client, LM80_REG_FANDIV) &
- ~(3 << (2 * (nr + 1)))) | (data->fan_div[nr] << (2 * (nr + 1)));
+ rv = lm80_read_value(client, LM80_REG_FANDIV);
+ if (rv < 0)
+ return rv;
+ reg = (rv & ~(3 << (2 * (nr + 1))))
+ | (data->fan_div[nr] << (2 * (nr + 1)));
lm80_write_value(client, LM80_REG_FANDIV, reg);
/* Restore fan_min */
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