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-rw-r--r--drivers/iio/kfifo_buf.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/iio/kfifo_buf.c b/drivers/iio/kfifo_buf.c
index 6ec763f1202a..63da42498a9a 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);