Merge branch 'linus' into sched/core, to resolve conflicts

Conflicts:
	kernel/sysctl.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>

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;