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linux/sound/core/jack.c
Takashi Iwai 32b8544296 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>
2013-11-14 17:22:45 +01:00

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/*
* Jack abstraction layer
*
* Copyright 2008 Wolfson Microelectronics
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <sound/jack.h>
#include <sound/core.h>
static int jack_switch_types[SND_JACK_SWITCH_TYPES] = {
SW_HEADPHONE_INSERT,
SW_MICROPHONE_INSERT,
SW_LINEOUT_INSERT,
SW_JACK_PHYSICAL_INSERT,
SW_VIDEOOUT_INSERT,
SW_LINEIN_INSERT,
};
static int snd_jack_dev_disconnect(struct snd_device *device)
{
struct snd_jack *jack = device->device_data;
if (!jack->input_dev)
return 0;
/* If the input device is registered with the input subsystem
* then we need to use a different deallocator. */
if (jack->registered)
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);
return 0;
}
static int snd_jack_dev_register(struct snd_device *device)
{
struct snd_jack *jack = device->device_data;
struct snd_card *card = device->card;
int err, i;
snprintf(jack->name, sizeof(jack->name), "%s %s",
card->shortname, jack->id);
jack->input_dev->name = jack->name;
/* Default to the sound card device. */
if (!jack->input_dev->dev.parent)
jack->input_dev->dev.parent = snd_card_get_device_link(card);
/* Add capabilities for any keys that are enabled */
for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
int testbit = SND_JACK_BTN_0 >> i;
if (!(jack->type & testbit))
continue;
if (!jack->key[i])
jack->key[i] = BTN_0 + i;
input_set_capability(jack->input_dev, EV_KEY, jack->key[i]);
}
err = input_register_device(jack->input_dev);
if (err == 0)
jack->registered = 1;
return err;
}
/**
* snd_jack_new - Create a new jack
* @card: the card instance
* @id: an identifying string for this jack
* @type: a bitmask of enum snd_jack_type values that can be detected by
* this jack
* @jjack: Used to provide the allocated jack object to the caller.
*
* Creates a new jack object.
*
* Return: Zero if successful, or a negative error code on failure.
* On success @jjack will be initialised.
*/
int snd_jack_new(struct snd_card *card, const char *id, int type,
struct snd_jack **jjack)
{
struct snd_jack *jack;
int err;
int i;
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);
if (jack == NULL)
return -ENOMEM;
jack->id = kstrdup(id, GFP_KERNEL);
jack->input_dev = input_allocate_device();
if (jack->input_dev == NULL) {
err = -ENOMEM;
goto fail_input;
}
jack->input_dev->phys = "ALSA";
jack->type = type;
for (i = 0; i < SND_JACK_SWITCH_TYPES; i++)
if (type & (1 << i))
input_set_capability(jack->input_dev, EV_SW,
jack_switch_types[i]);
err = snd_device_new(card, SNDRV_DEV_JACK, jack, &ops);
if (err < 0)
goto fail_input;
*jjack = jack;
return 0;
fail_input:
input_free_device(jack->input_dev);
kfree(jack->id);
kfree(jack);
return err;
}
EXPORT_SYMBOL(snd_jack_new);
/**
* snd_jack_set_parent - Set the parent device for a jack
*
* @jack: The jack to configure
* @parent: The device to set as parent for the jack.
*
* Set the parent for the jack devices in the device tree. This
* function is only valid prior to registration of the jack. If no
* parent is configured then the parent device will be the sound card.
*/
void snd_jack_set_parent(struct snd_jack *jack, struct device *parent)
{
WARN_ON(jack->registered);
jack->input_dev->dev.parent = parent;
}
EXPORT_SYMBOL(snd_jack_set_parent);
/**
* snd_jack_set_key - Set a key mapping on a jack
*
* @jack: The jack to configure
* @type: Jack report type for this key
* @keytype: Input layer key type to be reported
*
* Map a SND_JACK_BTN_ button type to an input layer key, allowing
* reporting of keys on accessories via the jack abstraction. If no
* mapping is provided but keys are enabled in the jack type then
* BTN_n numeric buttons will be reported.
*
* If jacks are not reporting via the input API this call will have no
* effect.
*
* Note that this is intended to be use by simple devices with small
* numbers of keys that can be reported. It is also possible to
* access the input device directly - devices with complex input
* capabilities on accessories should consider doing this rather than
* using this abstraction.
*
* This function may only be called prior to registration of the jack.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_jack_set_key(struct snd_jack *jack, enum snd_jack_types type,
int keytype)
{
int key = fls(SND_JACK_BTN_0) - fls(type);
WARN_ON(jack->registered);
if (!keytype || key >= ARRAY_SIZE(jack->key))
return -EINVAL;
jack->type |= type;
jack->key[key] = keytype;
return 0;
}
EXPORT_SYMBOL(snd_jack_set_key);
/**
* snd_jack_report - Report the current status of a jack
*
* @jack: The jack to report status for
* @status: The current status of the jack
*/
void snd_jack_report(struct snd_jack *jack, int status)
{
int i;
if (!jack)
return;
for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
int testbit = SND_JACK_BTN_0 >> i;
if (jack->type & testbit)
input_report_key(jack->input_dev, jack->key[i],
status & testbit);
}
for (i = 0; i < ARRAY_SIZE(jack_switch_types); i++) {
int testbit = 1 << i;
if (jack->type & testbit)
input_report_switch(jack->input_dev,
jack_switch_types[i],
status & testbit);
}
input_sync(jack->input_dev);
}
EXPORT_SYMBOL(snd_jack_report);
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("Jack detection support for ALSA");
MODULE_LICENSE("GPL");
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