[PATCH] ALSA:usb-audio:check urb before kill it
Similar to commit<124751d5e>, there should be a check for urb before kill it.
Signed-off-by: Defang Bo bodefang@126.com --- 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)
Similar to commit<124751d5e>, there should be a check for urb before kill it.
I suggest to reconsider this change description. How does it fit to the information “may be NULL” from the function documentation? https://elixir.bootlin.com/linux/v5.10.3/source/drivers/usb/core/urb.c#L677
Regards, Markus
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@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
participants (3)
-
Defang Bo
-
Markus Elfring
-
Takashi Iwai