On Fri, Feb 27, 2015 at 09:58:38AM +0100, Oliver Neukum wrote:

On Fri, 2015-02-27 at 15:42 +0900, gyungoh@gmail.com wrote:

quoted

+static ssize_t sky81452_bl_store_enable(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t
count)
+{
+       struct regmap *regmap = bl_get_data(to_backlight_device(dev));
+       unsigned long value;
+       int ret;
+
+       ret = kstrtoul(buf, 16, &value);
+       if (IS_ERR_VALUE(ret))
+               return ret;

No range checking?

It doesn't need it. below regmap_update_bits() is masking the value.

quoted

+
+       ret = regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN,
+                                       value << CTZ(SKY81452_EN));
+       if (IS_ERR_VALUE(ret))
+               return ret;
+
+       return count;
+}

	Regards
		Oliver