diff options
Diffstat (limited to 'drivers/staging/comedi/comedi_fops.c')
| -rw-r--r-- | drivers/staging/comedi/comedi_fops.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index bd89e785fe6c..b1e8cdbd1ce7 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1839,7 +1839,7 @@ static unsigned int comedi_poll(struct file *file, poll_table *wait) } s = comedi_read_subdevice(info); - if (s) { + if (s && s->async) { poll_wait(file, &s->async->wait_head, wait); if (!s->busy || !comedi_is_subdevice_running(s) || comedi_buf_read_n_available(s->async) > 0) @@ -1847,7 +1847,7 @@ static unsigned int comedi_poll(struct file *file, poll_table *wait) } s = comedi_write_subdevice(info); - if (s) { + if (s && s->async) { unsigned int bps = bytes_per_sample(s->async->subdevice); poll_wait(file, &s->async->wait_head, wait); @@ -1882,7 +1882,7 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, } s = comedi_write_subdevice(info); - if (!s) + if (!s || !s->async) return -EIO; async = s->async; @@ -1977,7 +1977,7 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes, } s = comedi_read_subdevice(info); - if (!s) + if (!s || !s->async) return -EIO; async = s->async; |