diff options
Diffstat (limited to 'drivers/iio/industrialio-buffer.c')
| -rw-r--r-- | drivers/iio/industrialio-buffer.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 7f9152c3c4d3..c67d83bdc8f0 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -37,6 +37,14 @@ static bool iio_buffer_is_active(struct iio_buffer *buf) return !list_empty(&buf->buffer_list); } +static bool iio_buffer_data_available(struct iio_buffer *buf) +{ + if (buf->access->data_available) + return buf->access->data_available(buf); + + return buf->stufftoread; +} + /** * iio_buffer_read_first_n_outer() - chrdev read for buffer access * @@ -48,13 +56,34 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf, { struct iio_dev *indio_dev = filp->private_data; struct iio_buffer *rb = indio_dev->buffer; + int ret; if (!indio_dev->info) return -ENODEV; if (!rb || !rb->access->read_first_n) return -EINVAL; - return rb->access->read_first_n(rb, n, buf); + + do { + if (!iio_buffer_data_available(rb)) { + if (filp->f_flags & O_NONBLOCK) + return -EAGAIN; + + ret = wait_event_interruptible(rb->pollq, + iio_buffer_data_available(rb) || + indio_dev->info == NULL); + if (ret) + return ret; + if (indio_dev->info == NULL) + return -ENODEV; + } + + ret = rb->access->read_first_n(rb, n, buf); + if (ret == 0 && (filp->f_flags & O_NONBLOCK)) + ret = -EAGAIN; + } while (ret == 0); + + return ret; } /** @@ -70,7 +99,7 @@ unsigned int iio_buffer_poll(struct file *filp, return -ENODEV; poll_wait(filp, &rb->pollq, wait); - if (rb->stufftoread) + if (iio_buffer_data_available(rb)) return POLLIN | POLLRDNORM; /* need a way of knowing if there may be enough data... */ return 0; |