[PATCH] ALSA:usb-audio:check urb before kill it

[Takashi Iwai]

On Sun, 27 Dec 2020 14:04:59 +0100,
Defang Bo wrote:
> 
> Similar to commit<124751d5e>, there should be a check for urb before kill it.
> 
> Signed-off-by: Defang Bo <bodefang at 126.com>

usb_kill_urb() accepts the NULL urb pointer, so the NULL check in the
caller side is basically superfluous.


thanks,

Takashi

> ---
>  sound/usb/mixer.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
> index 81e987e..0223ef3 100644
> --- a/sound/usb/mixer.c
> +++ b/sound/usb/mixer.c
> @@ -3589,8 +3589,10 @@ void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer)
>  /* stop any bus activity of a mixer */
>  static void snd_usb_mixer_inactivate(struct usb_mixer_interface *mixer)
>  {
> -	usb_kill_urb(mixer->urb);
> -	usb_kill_urb(mixer->rc_urb);
> +	if (mixer->urb)
> +		usb_kill_urb(mixer->urb);
> +	if (mixer->rc_urb)
> +		usb_kill_urb(mixer->rc_urb);
>  }
>  
>  static int snd_usb_mixer_activate(struct usb_mixer_interface *mixer)
> -- 
> 2.7.4
>