rem: if (!dev->reg_is_valid(dev, reg))
add: if (!ac97_reg_is_valid(dev, reg))
context: ac97_reg_cached_write(ac97_dev *dev, uint8 reg, uint16 value){	if (!dev->reg_is_valid(dev, reg))		return;	dev->reg_write(dev->cookie, reg, value);	dev->reg_cache[reg] = value;}