diff options
| -rw-r--r-- | sound/firewire/tascam/tascam-hwdep.c | 38 |
1 files changed, 26 insertions, 12 deletions
diff --git a/sound/firewire/tascam/tascam-hwdep.c b/sound/firewire/tascam/tascam-hwdep.c index 9afa827af05d..8f34cede2e9f 100644 --- a/sound/firewire/tascam/tascam-hwdep.c +++ b/sound/firewire/tascam/tascam-hwdep.c @@ -16,14 +16,30 @@ #include "tascam.h" +static long tscm_hwdep_read_locked(struct snd_tscm *tscm, char __user *buf, + long count, loff_t *offset) +{ + struct snd_firewire_event_lock_status event = { + .type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS, + }; + + event.status = (tscm->dev_lock_count > 0); + tscm->dev_lock_changed = false; + count = min_t(long, count, sizeof(event)); + + spin_unlock_irq(&tscm->lock); + + if (copy_to_user(buf, &event, count)) + return -EFAULT; + + return count; +} + static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count, loff_t *offset) { struct snd_tscm *tscm = hwdep->private_data; DEFINE_WAIT(wait); - union snd_firewire_event event = { - .lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS, - }; spin_lock_irq(&tscm->lock); @@ -37,15 +53,13 @@ static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count, spin_lock_irq(&tscm->lock); } - event.lock_status.status = (tscm->dev_lock_count > 0); - tscm->dev_lock_changed = false; - - spin_unlock_irq(&tscm->lock); - - count = min_t(long, count, sizeof(event.lock_status)); - - if (copy_to_user(buf, &event, count)) - return -EFAULT; + // NOTE: The acquired lock should be released in callee side. + if (tscm->dev_lock_changed) { + count = tscm_hwdep_read_locked(tscm, buf, count, offset); + } else { + spin_unlock_irq(&tscm->lock); + count = 0; + } return count; } |