Subject: Re: [PATCH] net: wan: framer: pef2256: Fix missing mfd_remove_devices() call

From: Herve Codina <[email-masked]>
Date: Mon, 3 Nov 2025 12:43:16 +0100

Hi Haotian,

On Mon,  3 Nov 2025 19:18:44 +0800
Haotian Zhang <[email-masked]> wrote:

> The driver calls mfd_add_devices() but fails to call mfd_remove_devices()
> in error paths after successful MFD device registration and in the remove
> function. This leads to resource leaks where MFD child devices are not
> properly unregistered.
> 
> Add mfd_remove_devices() call in the error path after mfd_add_devices()
> succeeds, and add the missing mfd_remove_devices() call in pef2256_remove()
> to properly clean up MFD devices.
> 
> Fixes: c96e976d9a05 ("net: wan: framer: Add support for the Lantiq PEF2256 framer")
> Signed-off-by: Haotian Zhang <[email-masked]>
> ---
>  drivers/net/wan/framer/pef2256/pef2256.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/wan/framer/pef2256/pef2256.c b/drivers/net/wan/framer/pef2256/pef2256.c
> index 1e4c8e85d598..d43fbf9bb27d 100644
> --- a/drivers/net/wan/framer/pef2256/pef2256.c
> +++ b/drivers/net/wan/framer/pef2256/pef2256.c
> @@ -821,27 +821,34 @@ static int pef2256_probe(struct platform_device *pdev)
>  
>  	ret = pef2256_setup_e1(pef2256);
>  	if (ret)
> -		return ret;
> +		goto err_mfd_remove;
>  
>  	framer_provider = devm_framer_provider_of_register(pef2256->dev,
>  							   framer_provider_simple_of_xlate);
> -	if (IS_ERR(framer_provider))
> -		return PTR_ERR(framer_provider);
> +	if (IS_ERR(framer_provider)) {
> +		ret = PTR_ERR(framer_provider);
> +		goto err_mfd_remove;
> +	}
>  
>  	/* Add audio devices */
>  	ret = pef2256_add_audio_devices(pef2256);
>  	if (ret < 0) {
>  		dev_err(pef2256->dev, "add audio devices failed (%d)\n", ret);
> -		return ret;
> +		goto err_mfd_remove;
>  	}
>  
>  	return 0;
> +
> +err_mfd_remove:
> +	mfd_remove_devices(pef2256->dev);
> +	return ret;
>  }
>  
>  static void pef2256_remove(struct platform_device *pdev)
>  {
>  	struct pef2256 *pef2256 = platform_get_drvdata(pdev);
>  
> +	mfd_remove_devices(pef2256->dev);
>  	/* Disable interrupts */
>  	pef2256_write8(pef2256, PEF2256_IMR0, 0xff);
>  	pef2256_write8(pef2256, PEF2256_IMR1, 0xff);

Thanks for the patch.

Instead of calling mfd_remove_devices() in the error path and the remove()
function, can you replace the mfd_add_devices() call by the device managed
variant devm_mfd_add_devices()?

The device managed variant will handle the removal.

Best regards,
Hervé