Re: [PATCH 2/2] iio: kfifo - add poll support.

[Marek Vasut <marex@denx.de>]

Dear Jonathan Cameron,

> This buffer implementation was missing poll support.
> 
> Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Was this ever applied ?

> ---
>  drivers/iio/kfifo_buf.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/kfifo_buf.c b/drivers/iio/kfifo_buf.c
> index 6ec763f..63da424 100644
> --- a/drivers/iio/kfifo_buf.c
> +++ b/drivers/iio/kfifo_buf.c
> @@ -6,6 +6,7 @@
>  #include <linux/kfifo.h>
>  #include <linux/mutex.h>
>  #include <linux/iio/kfifo_buf.h>
> +#include <linux/sched.h>
> 
>  struct iio_kfifo {
>  	struct iio_buffer buffer;
> @@ -36,6 +37,7 @@ static int iio_request_update_kfifo(struct iio_buffer *r)
>  	kfifo_free(&buf->kf);
>  	ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
>  				   buf->buffer.length);
> +	r->stufftoread = false;
>  error_ret:
>  	return ret;
>  }
> @@ -82,6 +84,9 @@ static int iio_set_bytes_per_datum_kfifo(struct
> iio_buffer *r, size_t bpd)
> 
>  static int iio_set_length_kfifo(struct iio_buffer *r, int length)
>  {
> +	/* Avoid an invalid state */
> +	if (length < 2)
> +		length = 2;
>  	if (r->length != length) {
>  		r->length = length;
>  		iio_mark_update_needed_kfifo(r);
> @@ -98,6 +103,8 @@ static int iio_store_to_kfifo(struct iio_buffer *r,
>  	ret = kfifo_in(&kf->kf, data, 1);
>  	if (ret != 1)
>  		return -EBUSY;
> +	r->stufftoread = true;
> +	wake_up_interruptible(&r->pollq);
> 
>  	return 0;
>  }
> @@ -115,6 +122,12 @@ static int iio_read_first_n_kfifo(struct iio_buffer
> *r, if (ret < 0)
>  		return ret;
> 
> +	if (kfifo_is_empty(&kf->kf))
> +		r->stufftoread = false;
> +	/* verify it is still empty to avoid race */
> +	if (!kfifo_is_empty(&kf->kf))
> +		r->stufftoread = true;
> +
>  	return copied;
>  }
> 
> @@ -139,7 +152,7 @@ struct iio_buffer *iio_kfifo_allocate(struct iio_dev
> *indio_dev) iio_buffer_init(&kf->buffer);
>  	kf->buffer.attrs = &iio_kfifo_attribute_group;
>  	kf->buffer.access = &kfifo_access_funcs;
> -
> +	kf->buffer.length = 2;
>  	return &kf->buffer;
>  }
>  EXPORT_SYMBOL(iio_kfifo_allocate);

Best regards,
Marek Vasut