On Sat, May 29, 2021 at 5:35 AM 慕冬亮 <mudongliangabcd@xxxxxxxxx> wrote: > > > > > On May 28, 2021, at 10:05 PM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > > > On Fri, May 28, 2021 at 09:50:49PM +0800, Dongliang Mu wrote: > >> > >> Can you please give some advise on how to fix this WARN issue? > > > > But it feels like it spoils the fun if I write the commit... Anyway: > > It’s fine. I am still in the learning process. It’s also good to learn experience by comparing your patch and my patch. > > > > > regards, > > dan carpenter > > > > diff --git a/sound/core/control_led.c b/sound/core/control_led.c > > index 25f57c14f294..dd357abc1b58 100644 > > --- a/sound/core/control_led.c > > +++ b/sound/core/control_led.c > > @@ -740,6 +740,7 @@ static int __init snd_ctl_led_init(void) > > for (; group > 0; group--) { > > led = &snd_ctl_leds[group - 1]; > > device_del(&led->dev); > > + device_put(&led->dev); > > } > > device_del(&snd_ctl_led_dev); > > return -ENOMEM; > > @@ -768,6 +769,7 @@ static void __exit snd_ctl_led_exit(void) > > for (group = 0; group < MAX_LED; group++) { > > led = &snd_ctl_leds[group]; > > device_del(&led->dev); > > + device_put(&led->dev); > > } > > device_del(&snd_ctl_led_dev); > > snd_ctl_led_clean(NULL); Hi Dan, I tried this patch, and it still triggers the memleak. My understanding is that the device object is already freed in the snd_ctl_led_sysfs_remove. > > Does this patch mean I should add device_put in the init and exit function other than snd_ctl_led_sysfs_remove? This will cause device_release bypass the release method checking? >