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ALSA: jack: Unregister input device at disconnection 

The recent change in sysfs triggered a kernel WARNING at unloading a
sound driver like

  WARNING: CPU: 3 PID: 2247 at fs/sysfs/group.c:214 sysfs_remove_group+0xe8/0xf0()
  sysfs group ffffffff81ab7b20 not found for kobject 'event14'

for each jack instance.  It's because the unregistration of jack input
device is done in dev_free callback, which is called after
snd_card_disconnect().  Since device_unregister(card->card_dev) is
called in snd_card_disconnect(), the whole sysfs entries belonging to
card->card_dev have been already removed recursively.  Thus this
results in a warning as input_unregister_device() yet tries to
unregister the already removed sysfs entry.

For fixing this mess, we need to unregister the jack input device at
dev_disconnect callback so that it's called before unregistering the
card->card_dev.

Reviwed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2013-11-14 15:35:46 +01:00
parent 6408eac266
commit 32b8544296
1 changed files with 16 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
sound/core/jack.c
View File

@ -34,12 +34,12 @@ static int jack_switch_types[SND_JACK_SWITCH_TYPES] = {
SW_LINEIN_INSERT,
};
static int snd_jack_dev_free(struct snd_device *device)
static int snd_jack_dev_disconnect(struct snd_device *device)
{
struct snd_jack *jack = device->device_data;
if (jack->private_free)
jack->private_free(jack);
if (!jack->input_dev)
return 0;
/* If the input device is registered with the input subsystem
* then we need to use a different deallocator. */
@ -47,6 +47,18 @@ static int snd_jack_dev_free(struct snd_device *device)
input_unregister_device(jack->input_dev);
else
input_free_device(jack->input_dev);
jack->input_dev = NULL;
return 0;
}
static int snd_jack_dev_free(struct snd_device *device)
{
struct snd_jack *jack = device->device_data;
if (jack->private_free)
jack->private_free(jack);
snd_jack_dev_disconnect(device);
kfree(jack->id);
kfree(jack);
@ -110,6 +122,7 @@ int snd_jack_new(struct snd_card *card, const char *id, int type,
static struct snd_device_ops ops = {
.dev_free = snd_jack_dev_free,
.dev_register = snd_jack_dev_register,
.dev_disconnect = snd_jack_dev_disconnect,
};
jack = kzalloc(sizeof(struct snd_jack), GFP_KERNEL);