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>
diff --git a/sound/core/jack.c b/sound/core/jack.c
index b35fe73..8658578 100644
--- a/sound/core/jack.c
+++ b/sound/core/jack.c
@@ -34,12 +34,12 @@
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 @@
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 @@
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);