[alsa-devel] [PATCH 3/3] ALSA: Use standard device refcount for card accounting
Takashi Iwai
tiwai at suse.de
Wed Feb 12 12:20:13 CET 2014
Drop the own refcount but use the standard device refcounting via
get_device() and put_device(). Introduce a new completion to snd_card
instead of the wait queue for syncing the last release, which is used
in snd_card_free().
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
include/sound/core.h | 7 +++----
sound/core/init.c | 53 ++++++++++++++------------------------------------
sound/core/sound.c | 2 +-
sound/core/sound_oss.c | 2 +-
4 files changed, 20 insertions(+), 44 deletions(-)
diff --git a/include/sound/core.h b/include/sound/core.h
index f072e596f21a..f410a49862fd 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -42,6 +42,7 @@
/* forward declarations */
struct pci_dev;
struct module;
+struct completion;
/* device allocation stuff */
@@ -126,9 +127,7 @@ struct snd_card {
state */
spinlock_t files_lock; /* lock the files for this card */
int shutdown; /* this card is going down */
- int free_on_last_close; /* free in context of file_release */
- wait_queue_head_t shutdown_sleep;
- atomic_t refcount; /* refcount for disconnection */
+ struct completion *release_completion;
struct device *dev; /* device assigned to this card */
struct device card_dev; /* cardX object for sysfs */
bool registered; /* card_dev is registered? */
@@ -302,7 +301,7 @@ int snd_card_info_done(void);
int snd_component_add(struct snd_card *card, const char *component);
int snd_card_file_add(struct snd_card *card, struct file *file);
int snd_card_file_remove(struct snd_card *card, struct file *file);
-void snd_card_unref(struct snd_card *card);
+#define snd_card_unref(card) put_device(&(card)->card_dev)
#define snd_card_set_dev(card, devptr) ((card)->dev = (devptr))
diff --git a/sound/core/init.c b/sound/core/init.c
index 46a9e7cb1c04..3fdb4e2ce5ea 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -28,6 +28,7 @@
#include <linux/time.h>
#include <linux/ctype.h>
#include <linux/pm.h>
+#include <linux/completion.h>
#include <sound/core.h>
#include <sound/control.h>
@@ -235,8 +236,6 @@ int snd_card_new(struct device *parent, int idx, const char *xid,
INIT_LIST_HEAD(&card->ctl_files);
spin_lock_init(&card->files_lock);
INIT_LIST_HEAD(&card->files_list);
- init_waitqueue_head(&card->shutdown_sleep);
- atomic_set(&card->refcount, 0);
#ifdef CONFIG_PM
mutex_init(&card->power_lock);
init_waitqueue_head(&card->power_sleep);
@@ -466,58 +465,36 @@ static int snd_card_do_free(struct snd_card *card)
snd_printk(KERN_WARNING "unable to free card info\n");
/* Not fatal error */
}
+ if (card->release_completion)
+ complete(card->release_completion);
kfree(card);
return 0;
}
-/**
- * snd_card_unref - release the reference counter
- * @card: the card instance
- *
- * Decrements the reference counter. When it reaches to zero, wake up
- * the sleeper and call the destructor if needed.
- */
-void snd_card_unref(struct snd_card *card)
-{
- if (atomic_dec_and_test(&card->refcount)) {
- wake_up(&card->shutdown_sleep);
- if (card->free_on_last_close)
- put_device(&card->card_dev);
- }
-}
-EXPORT_SYMBOL(snd_card_unref);
-
int snd_card_free_when_closed(struct snd_card *card)
{
- int ret;
-
- atomic_inc(&card->refcount);
- ret = snd_card_disconnect(card);
- if (ret) {
- atomic_dec(&card->refcount);
+ int ret = snd_card_disconnect(card);
+ if (ret)
return ret;
- }
-
- card->free_on_last_close = 1;
- if (atomic_dec_and_test(&card->refcount))
- put_device(&card->card_dev);
+ put_device(&card->card_dev);
return 0;
}
-
EXPORT_SYMBOL(snd_card_free_when_closed);
int snd_card_free(struct snd_card *card)
{
- int ret = snd_card_disconnect(card);
+ struct completion released;
+ int ret;
+
+ init_completion(&released);
+ card->release_completion = &released;
+ ret = snd_card_free_when_closed(card);
if (ret)
return ret;
-
/* wait, until all devices are ready for the free operation */
- wait_event(card->shutdown_sleep, !atomic_read(&card->refcount));
- put_device(&card->card_dev);
+ wait_for_completion(&released);
return 0;
}
-
EXPORT_SYMBOL(snd_card_free);
/* retrieve the last word of shortname or longname */
@@ -924,7 +901,7 @@ int snd_card_file_add(struct snd_card *card, struct file *file)
return -ENODEV;
}
list_add(&mfile->list, &card->files_list);
- atomic_inc(&card->refcount);
+ get_device(&card->card_dev);
spin_unlock(&card->files_lock);
return 0;
}
@@ -967,7 +944,7 @@ int snd_card_file_remove(struct snd_card *card, struct file *file)
return -ENOENT;
}
kfree(found);
- snd_card_unref(card);
+ put_device(&card->card_dev);
return 0;
}
diff --git a/sound/core/sound.c b/sound/core/sound.c
index 437c25ea6403..4aaa53161644 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -118,7 +118,7 @@ void *snd_lookup_minor_data(unsigned int minor, int type)
if (mreg && mreg->type == type) {
private_data = mreg->private_data;
if (private_data && mreg->card_ptr)
- atomic_inc(&mreg->card_ptr->refcount);
+ get_device(&mreg->card_ptr->card_dev);
} else
private_data = NULL;
mutex_unlock(&sound_mutex);
diff --git a/sound/core/sound_oss.c b/sound/core/sound_oss.c
index b19184d45f19..573a65eb2b79 100644
--- a/sound/core/sound_oss.c
+++ b/sound/core/sound_oss.c
@@ -55,7 +55,7 @@ void *snd_lookup_oss_minor_data(unsigned int minor, int type)
if (mreg && mreg->type == type) {
private_data = mreg->private_data;
if (private_data && mreg->card_ptr)
- atomic_inc(&mreg->card_ptr->refcount);
+ get_device(&mreg->card_ptr->card_dev);
} else
private_data = NULL;
mutex_unlock(&sound_oss_mutex);
--
1.8.5.2
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