[PATCH] w83792d: Add missing data access locks

Add missing data lock in w83792d driver to avoid unexpected
data change.

Signed-off-by: Yuan Mu <ymu@winbond.com.tw>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/hwmon/w83792d.c b/drivers/hwmon/w83792d.c
index 6cdef18..4ef884c 100644
--- a/drivers/hwmon/w83792d.c
+++ b/drivers/hwmon/w83792d.c
@@ -372,8 +372,10 @@
 	u32 val; \
 	 \
 	val = simple_strtoul(buf, NULL, 10); \
+	mutex_lock(&data->update_lock); \
 	data->in_##reg[nr] = SENSORS_LIMIT(IN_TO_REG(nr, val)/4, 0, 255); \
 	w83792d_write_value(client, W83792D_REG_IN_##REG[nr], data->in_##reg[nr]); \
+	mutex_unlock(&data->update_lock); \
 	 \
 	return count; \
 }
@@ -440,9 +442,11 @@
 	u32 val;
 
 	val = simple_strtoul(buf, NULL, 10);
+	mutex_lock(&data->update_lock);
 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
 	w83792d_write_value(client, W83792D_REG_FAN_MIN[nr],
 				data->fan_min[nr]);
+	mutex_unlock(&data->update_lock);
 
 	return count;
 }
@@ -475,6 +479,7 @@
 	u8 tmp_fan_div;
 
 	/* Save fan_min */
+	mutex_lock(&data->update_lock);
 	min = FAN_FROM_REG(data->fan_min[nr],
 			   DIV_FROM_REG(data->fan_div[nr]));
 
@@ -490,6 +495,7 @@
 	/* Restore fan_min */
 	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
 	w83792d_write_value(client, W83792D_REG_FAN_MIN[nr], data->fan_min[nr]);
+	mutex_unlock(&data->update_lock);
 
 	return count;
 }
@@ -544,10 +550,11 @@
 	s32 val;
 
 	val = simple_strtol(buf, NULL, 10);
-
+	mutex_lock(&data->update_lock);
 	data->temp1[nr] = TEMP1_TO_REG(val);
 	w83792d_write_value(client, W83792D_REG_TEMP1[nr],
 		data->temp1[nr]);
+	mutex_unlock(&data->update_lock);
 
 	return count;
 }
@@ -577,13 +584,14 @@
 	s32 val;
 
 	val = simple_strtol(buf, NULL, 10);
-
+	mutex_lock(&data->update_lock);
 	data->temp_add[nr][index] = TEMP_ADD_TO_REG_HIGH(val);
 	data->temp_add[nr][index+1] = TEMP_ADD_TO_REG_LOW(val);
 	w83792d_write_value(client, W83792D_REG_TEMP_ADD[nr][index],
 		data->temp_add[nr][index]);
 	w83792d_write_value(client, W83792D_REG_TEMP_ADD[nr][index+1],
 		data->temp_add[nr][index+1]);
+	mutex_unlock(&data->update_lock);
 
 	return count;
 }
@@ -682,6 +690,10 @@
 	u8 fan_cfg_tmp, cfg1_tmp, cfg2_tmp, cfg3_tmp, cfg4_tmp;
 
 	val = simple_strtoul(buf, NULL, 10);
+	if (val < 1 || val > 3)
+		return -EINVAL;
+
+	mutex_lock(&data->update_lock);
 	switch (val) {
 	case 1:
 		data->pwmenable[nr] = 0; /* manual mode */
@@ -692,8 +704,6 @@
 	case 3:
 		data->pwmenable[nr] = 1; /* thermal cruise/Smart Fan I */
 		break;
-	default:
-		return -EINVAL;
 	}
 	cfg1_tmp = data->pwmenable[0];
 	cfg2_tmp = (data->pwmenable[1]) << 2;
@@ -701,6 +711,7 @@
 	cfg4_tmp = w83792d_read_value(client,W83792D_REG_FAN_CFG) & 0xc0;
 	fan_cfg_tmp = ((cfg4_tmp | cfg3_tmp) | cfg2_tmp) | cfg1_tmp;
 	w83792d_write_value(client, W83792D_REG_FAN_CFG, fan_cfg_tmp);
+	mutex_unlock(&data->update_lock);
 
 	return count;
 }
@@ -794,12 +805,13 @@
 	u8 temp1 = 0, temp2 = 0;
 
 	val = simple_strtoul(buf, NULL, 10);
-
+	mutex_lock(&data->update_lock);
 	data->chassis_clear = SENSORS_LIMIT(val, 0 ,1);
 	temp1 = ((data->chassis_clear) << 7) & 0x80;
 	temp2 = w83792d_read_value(client,
 		W83792D_REG_CHASSIS_CLR) & 0x7f;
 	w83792d_write_value(client, W83792D_REG_CHASSIS_CLR, temp1 | temp2);
+	mutex_unlock(&data->update_lock);
 
 	return count;
 }
@@ -832,10 +844,12 @@
 	val = simple_strtoul(buf, NULL, 10);
 	target_tmp = val;
 	target_tmp = target_tmp & 0x7f;
+	mutex_lock(&data->update_lock);
 	target_mask = w83792d_read_value(client, W83792D_REG_THERMAL[nr]) & 0x80;
 	data->thermal_cruise[nr] = SENSORS_LIMIT(target_tmp, 0, 255);
 	w83792d_write_value(client, W83792D_REG_THERMAL[nr],
 		(data->thermal_cruise[nr]) | target_mask);
+	mutex_unlock(&data->update_lock);
 
 	return count;
 }
@@ -872,6 +886,7 @@
 	u8 tol_tmp, tol_mask;
 
 	val = simple_strtoul(buf, NULL, 10);
+	mutex_lock(&data->update_lock);
 	tol_mask = w83792d_read_value(client,
 		W83792D_REG_TOLERANCE[nr]) & ((nr == 1) ? 0x0f : 0xf0);
 	tol_tmp = SENSORS_LIMIT(val, 0, 15);
@@ -882,6 +897,7 @@
 	}
 	w83792d_write_value(client, W83792D_REG_TOLERANCE[nr],
 		tol_mask | tol_tmp);
+	mutex_unlock(&data->update_lock);
 
 	return count;
 }
@@ -920,11 +936,13 @@
 	u8 mask_tmp = 0;
 
 	val = simple_strtoul(buf, NULL, 10);
+	mutex_lock(&data->update_lock);
 	data->sf2_points[index][nr] = SENSORS_LIMIT(val, 0, 127);
 	mask_tmp = w83792d_read_value(client,
 					W83792D_REG_POINTS[index][nr]) & 0x80;
 	w83792d_write_value(client, W83792D_REG_POINTS[index][nr],
 		mask_tmp|data->sf2_points[index][nr]);
+	mutex_unlock(&data->update_lock);
 
 	return count;
 }
@@ -984,6 +1002,7 @@
 	u8 mask_tmp=0, level_tmp=0;
 
 	val = simple_strtoul(buf, NULL, 10);
+	mutex_lock(&data->update_lock);
 	data->sf2_levels[index][nr] = SENSORS_LIMIT((val * 15) / 100, 0, 15);
 	mask_tmp = w83792d_read_value(client, W83792D_REG_LEVELS[index][nr])
 		& ((nr==3) ? 0xf0 : 0x0f);
@@ -993,6 +1012,7 @@
 		level_tmp = data->sf2_levels[index][nr] << 4;
 	}
 	w83792d_write_value(client, W83792D_REG_LEVELS[index][nr], level_tmp | mask_tmp);
+	mutex_unlock(&data->update_lock);
 
 	return count;
 }