ALSA: jack: Unregister input device at disconnection (32b85442) · Commits · 戴 / test

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>

sound/core/jack.c

+16 −3

Original line number	Diff line number	Diff line
		@@ -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);

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