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authorTakashi Iwai <tiwai@suse.de>2010-04-07 20:52:08 +0400
committerTakashi Iwai <tiwai@suse.de>2010-04-09 12:28:36 +0400
commit4cf19b848f92641eeb2585949a09eedec57fb53a (patch)
treeaeaefaee475b6b89f482acc680ea26a785b5fb6f /sound/core
parent5b5cd553e3ac49e6a9bac148f07ab94d3d96dae5 (diff)
downloadlinux-4cf19b848f92641eeb2585949a09eedec57fb53a.tar.xz
ALSA: Remove BKL from open multiplexer
Use a local mutex instead of BKL. This should suffice since each device type has also its open_mutex. Also, a bit of clean-up of the legacy device auto-loading code. Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
-rw-r--r--sound/core/sound.c73
1 files changed, 38 insertions, 35 deletions
diff --git a/sound/core/sound.c b/sound/core/sound.c
index 563d1967a0ad..ac42af42b787 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -120,7 +120,29 @@ void *snd_lookup_minor_data(unsigned int minor, int type)
EXPORT_SYMBOL(snd_lookup_minor_data);
-static int __snd_open(struct inode *inode, struct file *file)
+#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;
@@ -129,55 +151,36 @@ static int __snd_open(struct inode *inode, struct file *file)
if (minor >= ARRAY_SIZE(snd_minors))
return -ENODEV;
+ mutex_lock(&sound_mutex);
mptr = snd_minors[minor];
if (mptr == NULL) {
-#ifdef CONFIG_MODULES
- 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);
if (file->f_op == NULL) {
file->f_op = old_fops;
- return -ENODEV;
+ err = -ENODEV;
}
- if (file->f_op->open)
+ mutex_unlock(&sound_mutex);
+ if (err < 0)
+ return err;
+
+ 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);
+ if (err) {
+ fops_put(file->f_op);
+ file->f_op = fops_get(old_fops);
+ }
}
fops_put(old_fops);
return err;
}
-
-/* BKL pushdown: nasty #ifdef avoidance wrapper */
-static int snd_open(struct inode *inode, struct file *file)
-{
- int ret;
-
- lock_kernel();
- ret = __snd_open(inode, file);
- unlock_kernel();
- return ret;
-}
-
static const struct file_operations snd_fops =
{
.owner = THIS_MODULE,