Re: [PATCH v2 3/4] iio: accel: kionix-kx022a: Prevent memory leak and fix state

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Fri, Aug 28, 2026 at 10:40:51AM +0300, Matti Vaittinen wrote:

> The driver allocates memory for samples at buffer enable path. If regmap
> operation fails in the kx022a_fifo_enable() at the buffer enable path, the
> allocated memory is never freed. Furthermore, the state information and
> previous hardware configuration(s) aren't undone, potentially leaving
> WMI interrupts and buffers enabled, or driver state flags wrong.
> 
> Free the memory and revert the hardware configuration and state flags on
> error path.

...

> static int kx022a_fifo_enable(struct kx022a_data *data)

With

	struct regmap *map = data->regmap;

>  	guard(mutex)(&data->mutex);
>  	ret = __kx022a_turn_on_off(data, false);
>  	if (ret)
> -		return ret;
> +		goto err_free_out;
>  
>  	/* Update watermark to HW */
>  	ret = kx022a_fifo_set_wmi(data);
>  	if (ret)
> -		return ret;
> +		goto err_wmi_out;
>  
>  	/* Enable buffer */
>  	ret = regmap_set_bits(data->regmap, data->chip_info->buf_cntl2,
>  			      KX022A_MASK_BUF_EN);
>  	if (ret)
> -		return ret;
> +		goto err_wmi_out;
>  
>  	data->state |= KX022A_STATE_FIFO;
>  	ret = regmap_set_bits(data->regmap, data->ien_reg,
>  			      KX022A_MASK_WMI);
>  	if (ret)
> -		return ret;
> +		goto err_buf_en_out;
>  
> -	return __kx022a_turn_on_off(data, true);
> +	ret = __kx022a_turn_on_off(data, true);
> +	if (ret)
> +		goto err_on_out;
> +
> +	return ret;
> +
> +err_on_out:
> +	regmap_clear_bits(data->regmap, data->ien_reg,
> +			  KX022A_MASK_WMI);

in particular this will be

	regmap_clear_bits(map, data->ien_reg, KX022A_MASK_WMI);

> +err_buf_en_out:
> +	regmap_clear_bits(data->regmap, data->chip_info->buf_cntl2,
> +			  KX022A_MASK_BUF_EN);

	regmap_clear_bits(map, data->chip_info->buf_cntl2, KX022A_MASK_BUF_EN);

Which saves a single line, and the followup may shorten the existing code even
more.

> +	data->state &= ~KX022A_STATE_FIFO;
> +err_wmi_out:
> +	__kx022a_turn_on_off(data, true);
> +err_free_out:
> +	kfree(data->fifo_buffer);
> +
> +	return ret;
>  }

-- 
With Best Regards,
Andy Shevchenko