On 2022/3/23 04:49, Rob Herring wrote:
+/* + * ls7a_gpio_i2c_set - set the state of a gpio pin indicated by mask + * @mask: gpio pin mask + */ +static void ls7a_gpio_i2c_set(struct lsdc_i2c * const li2c, int mask, int state) +{ + unsigned long flags; + u8 val; + + spin_lock_irqsave(&li2c->reglock, flags);What are you protecting? Doesn't the caller serialize calls to these functions?
This driver is ported from my work from my downstream work. Maxime also ask this question before, but i did not answer. He is right, protect single register access is not necessary. uncached access have done the job itself. so i remove it in V11 of my patch set. There are two way GPIO emulated i2c, I want the code between spin_lock_irqsave(&li2c->reglock, flags) and spin_unlock_irqrestore(&li2c->reglock, flags); finished in a atomic way, without any disruption. The two i2c should not have any influence each other. I write it by gut feeling, and luckily it works very well in practice.
