The async signal (SIGIO) support for ALSA control API has been never used by real applications, but yet it can be a cause of various potential deadlocks (although there hasn't been a bug report in this code path unlike timer and PCM). Let's drop the feature as the simplest solution to align with other APIs.
Signed-off-by: Takashi Iwai tiwai@suse.de --- include/sound/control.h | 1 - sound/core/control.c | 11 ----------- 2 files changed, 12 deletions(-)
diff --git a/include/sound/control.h b/include/sound/control.h index fcd3cce673ec..0390d4952dac 100644 --- a/include/sound/control.h +++ b/include/sound/control.h @@ -109,7 +109,6 @@ struct snd_ctl_file { int preferred_subdevice[SND_CTL_SUBDEV_ITEMS]; wait_queue_head_t change_sleep; spinlock_t read_lock; - struct fasync_struct *fasync; int subscribed; /* read interface is activated */ struct list_head events; /* waiting events for read */ }; diff --git a/sound/core/control.c b/sound/core/control.c index 4dba3a342458..3d3b8bf93f80 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -181,7 +181,6 @@ void snd_ctl_notify(struct snd_card *card, unsigned int mask, _found: wake_up(&ctl->change_sleep); spin_unlock(&ctl->read_lock); - kill_fasync(&ctl->fasync, SIGIO, POLL_IN); } read_unlock_irqrestore(&card->ctl_files_rwlock, flags); } @@ -2129,14 +2128,6 @@ int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn) EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat); #endif
-static int snd_ctl_fasync(int fd, struct file * file, int on) -{ - struct snd_ctl_file *ctl; - - ctl = file->private_data; - return fasync_helper(fd, file, on, &ctl->fasync); -} - /* return the preferred subdevice number if already assigned; * otherwise return -1 */ @@ -2264,7 +2255,6 @@ static const struct file_operations snd_ctl_f_ops = .poll = snd_ctl_poll, .unlocked_ioctl = snd_ctl_ioctl, .compat_ioctl = snd_ctl_ioctl_compat, - .fasync = snd_ctl_fasync, };
/* @@ -2302,7 +2292,6 @@ static int snd_ctl_dev_disconnect(struct snd_device *device) read_lock_irqsave(&card->ctl_files_rwlock, flags); list_for_each_entry(ctl, &card->ctl_files, list) { wake_up(&ctl->change_sleep); - kill_fasync(&ctl->fasync, SIGIO, POLL_ERR); } read_unlock_irqrestore(&card->ctl_files_rwlock, flags);