int
snd_seq_oss_read(seq_oss_devinfo_t *dp, char __user *buf, int count)
{
seq_oss_readq_t *readq = dp->readq;
int cnt, pos;
evrec_t *q;
unsigned long flags;
if (readq == NULL || ! is_read_mode(dp->file_mode))
return -EIO;
/* copy queued events to read buffer */
cnt = count;
pos = 0;
q = snd_seq_oss_readq_pick(readq, !is_nonblock_mode(dp->file_mode), &flags);
if (q == NULL)
return 0;
do {
int ev_len;
/* tansfer the data */
ev_len = ev_length(q);
if (copy_to_user(buf + pos, q, ev_len)) {
snd_seq_oss_readq_unlock(readq, flags);
break;
}
snd_seq_oss_readq_free(readq, flags);
pos += ev_len;
cnt -= ev_len;
if (cnt < ev_len)
break;
} while ((q = snd_seq_oss_readq_pick(readq, 0, &flags)) != NULL);
return count - cnt;
}
int
snd_seq_oss_read(struct seq_oss_devinfo *dp, char __user *buf, int count)
{
struct seq_oss_readq *readq = dp->readq;
int result = 0, err = 0;
int ev_len;
union evrec rec;
unsigned long flags;
if (readq == NULL || ! is_read_mode(dp->file_mode))
return -ENXIO;
while (count >= SHORT_EVENT_SIZE) {
snd_seq_oss_readq_lock(readq, flags);
err = snd_seq_oss_readq_pick(readq, &rec);
if (err == -EAGAIN &&
!is_nonblock_mode(dp->file_mode) && result == 0) {
snd_seq_oss_readq_unlock(readq, flags);
snd_seq_oss_readq_wait(readq);
snd_seq_oss_readq_lock(readq, flags);
if (signal_pending(current))
err = -ERESTARTSYS;
else
err = snd_seq_oss_readq_pick(readq, &rec);
}
if (err < 0) {
snd_seq_oss_readq_unlock(readq, flags);
break;
}
ev_len = ev_length(&rec);
if (ev_len < count) {
snd_seq_oss_readq_unlock(readq, flags);
break;
}
snd_seq_oss_readq_free(readq);
snd_seq_oss_readq_unlock(readq, flags);
if (copy_to_user(buf, &rec, ev_len)) {
err = -EFAULT;
break;
}
result += ev_len;
buf += ev_len;
count -= ev_len;
}
return result > 0 ? result : err;
}
