Re: [PATCH v5 6/6] i2c: Add driver for the RTL9300 I2C controller

[Markus Elfring]

…
> +++ b/drivers/i2c/busses/i2c-rtl9300.c
> @@ -0,0 +1,422 @@
…
> +static int rtl9300_i2c_smbus_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
> +				  char read_write, u8 command, int size,
> +				  union i2c_smbus_data *data)
> +{
…
> +	mutex_lock(&i2c->lock);
> +	if (chan->sda_pin != i2c->sda_pin) {
…
> +out_unlock:
> +	mutex_unlock(&i2c->lock);
> +
> +	return ret;
> +}
…

Under which circumstances would you become interested to apply a statement
like “guard(mutex)(&i2c->lock);”?
https://elixir.bootlin.com/linux/v6.11/source/include/linux/mutex.h#L196

Regards,
Markus