On 11/25/13 14:56, Lars-Peter Clausen wrote:
> Currently the IIO buffer interface only allows non-blocking reads. This patch
> adds support for blocking IO. In blocking mode the thread will go to sleep if no
> data is available and will wait for the buffer implementation to signal that new
> data is available by waking up the buffers waitqueue.
>
> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
Applied to the togreg branch of iio.git
Nice little bit of functionality. Thanks.
Jonathan
> ---
> drivers/iio/industrialio-buffer.c | 23 ++++++++++++++++++++++-
> 1 file changed, 22 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
> index 4dcc3a0..c67d83b 100644
> --- a/drivers/iio/industrialio-buffer.c
> +++ b/drivers/iio/industrialio-buffer.c
> @@ -56,13 +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;
> }
>
> /**
>
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