linux-kernel - Re: [PATCH] USB: serial: Remove redundant NULL check before release

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Date:   Thu, 9 Jun 2022 14:43:50 +0200
From:   Johan Hovold <johan@...nel.org>
To:     cgel.zte@...il.com
Cc:     gregkh@...uxfoundation.org, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org, Minghao Chi <chi.minghao@....com.cn>,
        Zeal Robot <zealci@....com.cn>
Subject: Re: [PATCH] USB: serial: Remove redundant NULL check before
 release_firmware() call

On Mon, Jun 06, 2022 at 01:43:15AM +0000, cgel.zte@...il.com wrote:
> From: Minghao Chi <chi.minghao@....com.cn>
> 
> release_firmware() checks for NULL pointers internally so checking
> before calling it is redundant.
> 
> Reported-by: Zeal Robot <zealci@....com.cn>

Cleanups do not deserve a Reported-by tag, and neither do reports that
are never posted to the mailing lists.

> Signed-off-by: Minghao Chi <chi.minghao@....com.cn>
> ---
>  drivers/usb/serial/mxuport.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/serial/mxuport.c b/drivers/usb/serial/mxuport.c
> index eb45a9b0005c..eb9090ab900f 100644
> --- a/drivers/usb/serial/mxuport.c
> +++ b/drivers/usb/serial/mxuport.c
> @@ -1109,8 +1109,7 @@ static int mxuport_probe(struct usb_serial *serial,
>  	 */
>  	usb_set_serial_data(serial, (void *)id->driver_info);
>  out:
> -	if (fw_p)
> -		release_firmware(fw_p);
> +	release_firmware(fw_p);

I think keeping this check is preferred here as it makes the intent of
code more clear (and you don't have to check the definition of
release_firmware() to make sure it's safe to pass in NULL).

>  	return err;
>  }

Johan