At Wed, 22 Oct 2014 08:36:50 +0200, Takashi Iwai wrote:
- When unloading a device there are numerous sysfs_remove_group issues:
usb 1-1.1: USB disconnect, device number 6 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 54 at /build/buildd/linux-3.16.0/fs/sysfs/group.c:219 sysfs_remove_group+0x99/0xa0() sysfs group ffffffff82cbd6e0 not found for kobject 'midi1'
(snip)
However this issue occured even without the patch applied.
Yes, there was a similar report, but we couldn't reproduce here. It's a Oops coming from OSS midi device. This is fairly harmless, but annoying. Could you give your kernel config? Maybe there's some difference.
I'm now checking this issue again, and I still couldn't reproduce it on my local machines. Could you give your kernel config if this still happens?
Also, as a blind shot: does the patch below give any difference?
thanks,
Takashi
--- diff --git a/sound/usb/card.c b/sound/usb/card.c index 69725d5fa2d6..475961afc886 100644 --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -595,13 +595,13 @@ static void usb_audio_disconnect(struct usb_interface *intf) up_write(&chip->shutdown_rwsem);
mutex_lock(®ister_mutex); + snd_card_disconnect(card); chip->num_interfaces--; if (chip->num_interfaces <= 0) { struct snd_usb_stream *as; struct snd_usb_endpoint *ep; struct usb_mixer_interface *mixer;
- snd_card_disconnect(card); /* release the pcm resources */ list_for_each_entry(as, &chip->pcm_list, list) { snd_usb_stream_disconnect(as);