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Diffstat (limited to 'sound/core/sound.c')
-rw-r--r--sound/core/sound.c158
1 files changed, 94 insertions, 64 deletions
diff --git a/sound/core/sound.c b/sound/core/sound.c
index 812f91b3de5..38ad1a0dd3f 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -23,18 +23,15 @@
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/device.h>
-#include <linux/moduleparam.h>
+#include <linux/module.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
-#include <sound/version.h>
#include <sound/control.h>
#include <sound/initval.h>
#include <linux/kmod.h>
#include <linux/mutex.h>
-#define SNDRV_OS_MINORS 256
-
static int major = CONFIG_SND_MAJOR;
int snd_major;
EXPORT_SYMBOL(snd_major);
@@ -60,14 +57,14 @@ EXPORT_SYMBOL(snd_ecards_limit);
static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
static DEFINE_MUTEX(sound_mutex);
-#ifdef CONFIG_KMOD
+#ifdef CONFIG_MODULES
/**
* snd_request_card - try to load the card module
* @card: the card number
*
* Tries to load the module "snd-card-X" for the given card number
- * via KMOD. Returns immediately if already loaded.
+ * via request_module. Returns immediately if already loaded.
*/
void snd_request_card(int card)
{
@@ -92,7 +89,7 @@ static void snd_request_other(int minor)
request_module(str);
}
-#endif /* request_module support */
+#endif /* modular kernel */
/**
* snd_lookup_minor_data - get user data of a registered device
@@ -101,6 +98,13 @@ static void snd_request_other(int minor)
*
* Checks that a minor device with the specified type is registered, and returns
* its user data pointer.
+ *
+ * This function increments the reference counter of the card instance
+ * if an associated instance with the given minor number and type is found.
+ * The caller must call snd_card_unref() appropriately later.
+ *
+ * Return: The user data pointer if the specified device is found. %NULL
+ * otherwise.
*/
void *snd_lookup_minor_data(unsigned int minor, int type)
{
@@ -111,9 +115,11 @@ void *snd_lookup_minor_data(unsigned int minor, int type)
return NULL;
mutex_lock(&sound_mutex);
mreg = snd_minors[minor];
- if (mreg && mreg->type == type)
+ if (mreg && mreg->type == type) {
private_data = mreg->private_data;
- else
+ if (private_data && mreg->card_ptr)
+ get_device(&mreg->card_ptr->card_dev);
+ } else
private_data = NULL;
mutex_unlock(&sound_mutex);
return private_data;
@@ -121,63 +127,81 @@ void *snd_lookup_minor_data(unsigned int minor, int type)
EXPORT_SYMBOL(snd_lookup_minor_data);
+#ifdef CONFIG_MODULES
+static struct snd_minor *autoload_device(unsigned int minor)
+{
+ int dev;
+ mutex_unlock(&sound_mutex); /* release lock temporarily */
+ dev = SNDRV_MINOR_DEVICE(minor);
+ if (dev == SNDRV_MINOR_CONTROL) {
+ /* /dev/aloadC? */
+ int card = SNDRV_MINOR_CARD(minor);
+ if (snd_cards[card] == NULL)
+ snd_request_card(card);
+ } else if (dev == SNDRV_MINOR_GLOBAL) {
+ /* /dev/aloadSEQ */
+ snd_request_other(minor);
+ }
+ mutex_lock(&sound_mutex); /* reacuire lock */
+ return snd_minors[minor];
+}
+#else /* !CONFIG_MODULES */
+#define autoload_device(minor) NULL
+#endif /* CONFIG_MODULES */
+
static int snd_open(struct inode *inode, struct file *file)
{
unsigned int minor = iminor(inode);
struct snd_minor *mptr = NULL;
- const struct file_operations *old_fops;
+ const struct file_operations *new_fops;
int err = 0;
if (minor >= ARRAY_SIZE(snd_minors))
return -ENODEV;
+ mutex_lock(&sound_mutex);
mptr = snd_minors[minor];
if (mptr == NULL) {
-#ifdef CONFIG_KMOD
- int dev = SNDRV_MINOR_DEVICE(minor);
- if (dev == SNDRV_MINOR_CONTROL) {
- /* /dev/aloadC? */
- int card = SNDRV_MINOR_CARD(minor);
- if (snd_cards[card] == NULL)
- snd_request_card(card);
- } else if (dev == SNDRV_MINOR_GLOBAL) {
- /* /dev/aloadSEQ */
- snd_request_other(minor);
- }
-#ifndef CONFIG_SND_DYNAMIC_MINORS
- /* /dev/snd/{controlC?,seq} */
- mptr = snd_minors[minor];
- if (mptr == NULL)
-#endif
-#endif
+ mptr = autoload_device(minor);
+ if (!mptr) {
+ mutex_unlock(&sound_mutex);
return -ENODEV;
+ }
}
- old_fops = file->f_op;
- file->f_op = fops_get(mptr->f_ops);
+ new_fops = fops_get(mptr->f_ops);
+ mutex_unlock(&sound_mutex);
+ if (!new_fops)
+ return -ENODEV;
+ replace_fops(file, new_fops);
+
if (file->f_op->open)
err = file->f_op->open(inode, file);
- if (err) {
- fops_put(file->f_op);
- file->f_op = fops_get(old_fops);
- }
- fops_put(old_fops);
return err;
}
static const struct file_operations snd_fops =
{
.owner = THIS_MODULE,
- .open = snd_open
+ .open = snd_open,
+ .llseek = noop_llseek,
};
#ifdef CONFIG_SND_DYNAMIC_MINORS
-static int snd_find_free_minor(void)
+static int snd_find_free_minor(int type)
{
int minor;
+ /* static minors for module auto loading */
+ if (type == SNDRV_DEVICE_TYPE_SEQUENCER)
+ return SNDRV_MINOR_SEQUENCER;
+ if (type == SNDRV_DEVICE_TYPE_TIMER)
+ return SNDRV_MINOR_TIMER;
+
for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
- /* skip minors still used statically for autoloading devices */
- if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL ||
- minor == SNDRV_MINOR_SEQUENCER)
+ /* skip static minors still used for module auto loading */
+ if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL)
+ continue;
+ if (minor == SNDRV_MINOR_SEQUENCER ||
+ minor == SNDRV_MINOR_TIMER)
continue;
if (!snd_minors[minor])
return minor;
@@ -195,20 +219,24 @@ static int snd_kernel_minor(int type, struct snd_card *card, int dev)
minor = type;
break;
case SNDRV_DEVICE_TYPE_CONTROL:
- snd_assert(card != NULL, return -EINVAL);
+ if (snd_BUG_ON(!card))
+ return -EINVAL;
minor = SNDRV_MINOR(card->number, type);
break;
case SNDRV_DEVICE_TYPE_HWDEP:
case SNDRV_DEVICE_TYPE_RAWMIDI:
case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
- snd_assert(card != NULL, return -EINVAL);
+ case SNDRV_DEVICE_TYPE_COMPRESS:
+ if (snd_BUG_ON(!card))
+ return -EINVAL;
minor = SNDRV_MINOR(card->number, type + dev);
break;
default:
return -EINVAL;
}
- snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL);
+ if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
+ return -EINVAL;
return minor;
}
#endif
@@ -226,7 +254,7 @@ static int snd_kernel_minor(int type, struct snd_card *card, int dev)
* Registers an ALSA device file for the given card.
* The operators have to be set in reg parameter.
*
- * Returns zero if successful, or a negative error code on failure.
+ * Return: Zero if successful, or a negative error code on failure.
*/
int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
const struct file_operations *f_ops,
@@ -236,7 +264,8 @@ int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
int minor;
struct snd_minor *preg;
- snd_assert(name, return -EINVAL);
+ if (snd_BUG_ON(!name))
+ return -EINVAL;
preg = kmalloc(sizeof *preg, GFP_KERNEL);
if (preg == NULL)
return -ENOMEM;
@@ -245,9 +274,10 @@ int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
preg->device = dev;
preg->f_ops = f_ops;
preg->private_data = private_data;
+ preg->card_ptr = card;
mutex_lock(&sound_mutex);
#ifdef CONFIG_SND_DYNAMIC_MINORS
- minor = snd_find_free_minor();
+ minor = snd_find_free_minor(type);
#else
minor = snd_kernel_minor(type, card, dev);
if (minor >= 0 && snd_minors[minor])
@@ -260,7 +290,7 @@ int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
}
snd_minors[minor] = preg;
preg->dev = device_create(sound_class, device, MKDEV(major, minor),
- "%s", name);
+ private_data, "%s", name);
if (IS_ERR(preg->dev)) {
snd_minors[minor] = NULL;
mutex_unlock(&sound_mutex);
@@ -269,9 +299,6 @@ int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
return minor;
}
- if (preg->dev)
- dev_set_drvdata(preg->dev, private_data);
-
mutex_unlock(&sound_mutex);
return 0;
}
@@ -305,7 +332,7 @@ static int find_snd_minor(int type, struct snd_card *card, int dev)
* Unregisters the device file already registered via
* snd_register_device().
*
- * Returns zero if sucecessful, or a negative error code on failure
+ * Return: Zero if successful, or a negative error code on failure.
*/
int snd_unregister_device(int type, struct snd_card *card, int dev)
{
@@ -328,22 +355,25 @@ int snd_unregister_device(int type, struct snd_card *card, int dev)
EXPORT_SYMBOL(snd_unregister_device);
-int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
- struct device_attribute *attr)
+/* get the assigned device to the given type and device number;
+ * the caller needs to release it via put_device() after using it
+ */
+struct device *snd_get_device(int type, struct snd_card *card, int dev)
{
- int minor, ret = -EINVAL;
- struct device *d;
+ int minor;
+ struct device *d = NULL;
mutex_lock(&sound_mutex);
minor = find_snd_minor(type, card, dev);
- if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)
- ret = device_create_file(d, attr);
+ if (minor >= 0) {
+ d = snd_minors[minor]->dev;
+ if (d)
+ get_device(d);
+ }
mutex_unlock(&sound_mutex);
- return ret;
-
+ return d;
}
-
-EXPORT_SYMBOL(snd_add_device_sysfs_file);
+EXPORT_SYMBOL(snd_get_device);
#ifdef CONFIG_PROC_FS
/*
@@ -431,7 +461,7 @@ static int __init alsa_sound_init(void)
snd_major = major;
snd_ecards_limit = cards_limit;
if (register_chrdev(major, "alsa", &snd_fops)) {
- snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
+ pr_err("ALSA core: unable to register native major device number %d\n", major);
return -EIO;
}
if (snd_info_init() < 0) {
@@ -440,7 +470,7 @@ static int __init alsa_sound_init(void)
}
snd_info_minor_register();
#ifndef MODULE
- printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
+ pr_info("Advanced Linux Sound Architecture Driver Initialized.\n");
#endif
return 0;
}
@@ -452,5 +482,5 @@ static void __exit alsa_sound_exit(void)
unregister_chrdev(major, "alsa");
}
-module_init(alsa_sound_init)
-module_exit(alsa_sound_exit)
+subsys_initcall(alsa_sound_init);
+module_exit(alsa_sound_exit);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 03:42:01 +0000