staging:iio: core. Allow for event chrdev obtaining ioctl if no buffer present.
Logic bug meant the chrdev would fail to open if there was no buffer support
in a driver or in the core. This meant the ioctl to get the event chrdev
would fail and hence events were not available.
V2: change error to -EINVAL to mark as unsuitable for reading rather than
not there. Both are true depending on how you look at it.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/iio/industrialio-buffer.c b/drivers/staging/iio/industrialio-buffer.c
index 9df0ce8..ecf1e2f 100644
--- a/drivers/staging/iio/industrialio-buffer.c
+++ b/drivers/staging/iio/industrialio-buffer.c
@@ -43,7 +43,7 @@
struct iio_dev *indio_dev = filp->private_data;
struct iio_buffer *rb = indio_dev->buffer;
- if (!rb->access->read_first_n)
+ if (!rb || !rb->access->read_first_n)
return -EINVAL;
return rb->access->read_first_n(rb, n, buf);
}
@@ -68,7 +68,7 @@
{
struct iio_buffer *rb = indio_dev->buffer;
if (!rb)
- return -EINVAL;
+ return 0;
if (rb->access->mark_in_use)
rb->access->mark_in_use(rb);
return 0;
@@ -78,6 +78,8 @@
{
struct iio_buffer *rb = indio_dev->buffer;
+ if (!rb)
+ return;
clear_bit(IIO_BUSY_BIT_POS, &rb->flags);
if (rb->access->unmark_in_use)
rb->access->unmark_in_use(rb);
