| @@ -35,6 +35,65 @@ static long tscm_hwdep_read_locked(struct snd_tscm *tscm, char __user *buf, · 34 unmodified lines |
| 35 | 35 | return count; |
| 36 | 36 | } |
| 37 | 37 | |
| 38 | +static long tscm_hwdep_read_queue(struct snd_tscm *tscm, char __user *buf, |
| 39 | + long remained, loff_t *offset) |
| 40 | +{ |
| 41 | + char __user *pos = buf; |
| 42 | + unsigned int type = SNDRV_FIREWIRE_EVENT_TASCAM_CONTROL; |
| 43 | + struct snd_firewire_tascam_change *entries = tscm->queue; |
| 44 | + long count; |
| 45 | + |
| 46 | + // At least, one control event can be copied. |
| 47 | + if (remained < sizeof(type) + sizeof(*entries)) { |
| 48 | + spin_unlock_irq(&tscm->lock); |
| 49 | + return -EINVAL; |
| 50 | + } |
| 51 | + |
| 52 | + // Copy the type field later. |
| 53 | + count = sizeof(type); |
| 54 | + remained -= sizeof(type); |
| 55 | + pos += sizeof(type); |
| 56 | + |
| 57 | + while (true) { |
| 58 | + unsigned int head_pos; |
| 59 | + unsigned int tail_pos; |
| 60 | + unsigned int length; |
| 61 | + |
| 62 | + if (tscm->pull_pos == tscm->push_pos) |
| 63 | + break; |
| 64 | + else if (tscm->pull_pos < tscm->push_pos) |
| 65 | + tail_pos = tscm->push_pos; |
| 66 | + else |
| 67 | + tail_pos = SND_TSCM_QUEUE_COUNT; |
| 68 | + head_pos = tscm->pull_pos; |
| 69 | + |
| 70 | + length = (tail_pos - head_pos) * sizeof(*entries); |
| 71 | + if (remained < length) |
| 72 | + length = rounddown(remained, sizeof(*entries)); |
| 73 | + if (length == 0) |
| 74 | + break; |
| 75 | + |
| 76 | + spin_unlock_irq(&tscm->lock); |
| 77 | + if (copy_to_user(pos, &entries[head_pos], length)) |
| 78 | + return -EFAULT; |
| 79 | + |
| 80 | + spin_lock_irq(&tscm->lock); |
| 81 | + |
| 82 | + tscm->pull_pos = tail_pos % SND_TSCM_QUEUE_COUNT; |
| 83 | + |
| 84 | + count += length; |
| 85 | + remained -= length; |
| 86 | + pos += length; |
| 87 | + } |
| 88 | + |
| 89 | + spin_unlock_irq(&tscm->lock); |
| 90 | + |
| 91 | + if (copy_to_user(buf, &type, sizeof(type))) |
| 92 | + return -EFAULT; |
| 93 | + |
| 94 | + return count; |
| 95 | +} |
| 96 | + |
| 38 | 97 | static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count, |
| 39 | 98 | loff_t *offset) |
| 40 | 99 | { |
| @@ -43,7 +102,7 @@ static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count, · 2 unmodified lines |
| 43 | 102 | |
| 44 | 103 | spin_lock_irq(&tscm->lock); |
| 45 | 104 | |
| 46 | | − while (!tscm->dev_lock_changed) { |
| 105 | + while (!tscm->dev_lock_changed && tscm->push_pos == tscm->pull_pos) { |
| 47 | 106 | prepare_to_wait(&tscm->hwdep_wait, &wait, TASK_INTERRUPTIBLE); |
| 48 | 107 | spin_unlock_irq(&tscm->lock); |
| 49 | 108 | schedule(); |
| @@ -56,6 +115,8 @@ static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count, · 6 unmodified lines |
| 56 | 115 | // NOTE: The acquired lock should be released in callee side. |
| 57 | 116 | if (tscm->dev_lock_changed) { |
| 58 | 117 | count = tscm_hwdep_read_locked(tscm, buf, count, offset); |
| 118 | + } else if (tscm->push_pos != tscm->pull_pos) { |
| 119 | + count = tscm_hwdep_read_queue(tscm, buf, count, offset); |
| 59 | 120 | } else { |
| 60 | 121 | spin_unlock_irq(&tscm->lock); |
| 61 | 122 | count = 0; |
| @@ -73,7 +134,7 @@ static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file, · 11 unmodified lines |
| 73 | 134 | poll_wait(file, &tscm->hwdep_wait, wait); |
| 74 | 135 | |
| 75 | 136 | spin_lock_irq(&tscm->lock); |
| 76 | | − if (tscm->dev_lock_changed) |
| 137 | + if (tscm->dev_lock_changed || tscm->push_pos != tscm->pull_pos) |
| 77 | 138 | events = EPOLLIN | EPOLLRDNORM; |
| 78 | 139 | else |
| 79 | 140 | events = 0; |