Re: [PATCH v2] iio: ccs811: Deassert WAKE GPIO on error paths

[Jonathan Cameron]

On Thu, 15 Oct 2026 18:00:23 +0530
Nikhil Gautam <nikhilgtr@xxxxxxxxx> wrote:

> Ensure the WAKE GPIO is deasserted when status polling fails or
> the data-ready timeout expires. Early returns could leave WAKE asserted,
> preventing the sensor from returning to its low-power state and
> potentially disrupting subsequent I2C transactions.

I need more on this point to know whether we care if an error
means we don't deassert the wake pin.

Why would failing to go to sleep break future transactions?
I'd kind of assume we'd awaken an already awake device (which sounds
idempotent but maybe not?) and carry on from there?

Jonathan

> 
> Route error paths through a common cleanup label to ensure WAKE is
> deasserted before returning.
> 
> Fixes: c6644f7201f3 ("iio: chemical: Add support for external Reset and Wakeup in CCS811")
> Signed-off-by: Nikhil Gautam <nikhilgtr@xxxxxxxxx>
> Reviewed-by: Joshua Crofts <joshua.crofts1@xxxxxxxxx>
> ---
>  drivers/iio/chemical/ccs811.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c
> index 998c9239c4c7..dad54f66ebb3 100644
> --- a/drivers/iio/chemical/ccs811.c
> +++ b/drivers/iio/chemical/ccs811.c
> @@ -198,18 +198,21 @@ static int ccs811_get_measurement(struct ccs811_data *data)
>  	while (tries-- > 0) {
>  		ret = i2c_smbus_read_byte_data(data->client, CCS811_STATUS);
>  		if (ret < 0)
> -			return ret;
> +			goto out;
>  
>  		if ((ret & CCS811_STATUS_DATA_READY) || tries == 0)
>  			break;
>  		msleep(100);
>  	}
> -	if (!(ret & CCS811_STATUS_DATA_READY))
> -		return -EIO;
> +	if (!(ret & CCS811_STATUS_DATA_READY)) {
> +		ret = -EIO;
> +		goto out;
> +	}
>  
>  	ret = i2c_smbus_read_i2c_block_data(data->client,
>  					    CCS811_ALG_RESULT_DATA, 8,
>  					    (char *)&data->buffer);
> +out:
>  	ccs811_set_wakeup(data, false);
>  
>  	return ret;