Re: [PATCH v7 1/3] iio: adc: ti-ads1100: Fix incorrect reading when datarate changed in single mode

[Andy Shevchenko]

On Tue, Jul 14, 2026 at 09:55:26PM +0200, Jakub Szczudlo wrote:
> When device is suspended and it is in single mode then changing
> datarate doesn't make it actually wait for new measurement, so to
> be sure that read after change is correct functions that changes
> datarate and gain will wait for a new data.

...

> +static int ads1100_poll_data_ready(struct ads1100_data *data)
> +{
> +	int data_rate_Hz = ads1100_data_rate[FIELD_GET(ADS1100_DR_MASK, data->config)];
> +	/* To be sure we wait 5 times more than data rate */
> +	unsigned long wait_time_us = DIV_ROUND_CLOSEST(USEC_PER_SEC, 5 * data_rate_Hz);
> +	int data_ready;
> +	u8 buffer[3];
> +	int ret;
> +
> +	/* To be sure that polled value will have value after config change */
> +	ret = i2c_master_recv(data->client, (char *)&buffer, sizeof(buffer));
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "I2C read fail: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = readx_poll_timeout(ads1100_new_data_is_ready, data,
> +				 data_ready, data_ready != 0,
> +				 wait_time_us, ADS1100_MAX_DRDY_TIMEOUT_US);
> +	if (ret)
> +		return ret;

> +	return data_ready < 0 ? data_ready : 0;

I would unroll this to if-cond as it will be more readable (to get that
data_ready is negative when it holds an error code).

	if (data_ready < 0)
		return data_ready;

	return 0;

> +}

-- 
With Best Regards,
Andy Shevchenko