Re: [PATCH] iio: adc: ti-ads1119: fix PM reference leak in buffer preenable

[Jonathan Cameron <jic23@kernel.org>]

On Wed,  3 Jun 2026 20:16:40 +0800
Guangshuo Li <lgs201920130244@gmail.com> wrote:

> ads1119_triggered_buffer_preenable() resumes the device with
> pm_runtime_resume_and_get() before starting a conversion.
> 
> If i2c_smbus_write_byte() fails, the function returns the error directly
> and leaves the runtime PM usage counter elevated. The matching
> postdisable callback is not called when preenable fails, so the reference
> is leaked and the device may remain runtime-active indefinitely.
> 
> Store the I2C transfer result in ret and drop the runtime PM reference on
> failure before returning the error.
> 
> Fixes: a9306887eba41 ("iio: adc: ti-ads1119: Add driver")
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Applied to the fixes-togreg branch of iio.git and marked for stable.

Note I may well drag these across to the togreg branch for the coming
merge window as I'm not really expecting to squeeze in another fixes
pull this cycle and all the fixes I currently have queued are for ancient
bugs.

> ---
>  drivers/iio/adc/ti-ads1119.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/adc/ti-ads1119.c b/drivers/iio/adc/ti-ads1119.c
> index 79be71b4de96..9324408cb3b0 100644
> --- a/drivers/iio/adc/ti-ads1119.c
> +++ b/drivers/iio/adc/ti-ads1119.c
> @@ -459,7 +459,11 @@ static int ads1119_triggered_buffer_preenable(struct iio_dev *indio_dev)
>  	if (ret)
>  		return ret;
>  
> -	return i2c_smbus_write_byte(st->client, ADS1119_CMD_START_SYNC);
> +	ret = i2c_smbus_write_byte(st->client, ADS1119_CMD_START_SYNC);
> +	if (ret)
> +		pm_runtime_put_autosuspend(dev);
> +
> +	return ret;
>  }
>  
>  static int ads1119_triggered_buffer_postdisable(struct iio_dev *indio_dev)