staging: iio: ring_sw: Fix incorrect test on successful read of last value, causes...

This is a bad one. The test means that almost no reads of the last
value ever succeed!  Result is an infinite loop.

Another one for the 'oops' category.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/iio/ring_sw.c b/drivers/staging/iio/ring_sw.c
index b104c3d..cf22c09 100644 (file)
--- a/drivers/staging/iio/ring_sw.c
+++ b/drivers/staging/iio/ring_sw.c
@@ -293,7 +293,7 @@ again:
                return -EAGAIN;
        memcpy(data, last_written_p_copy, ring->buf.bpd);
 
-       if (unlikely(ring->last_written_p >= last_written_p_copy))
+       if (unlikely(ring->last_written_p != last_written_p_copy))
                goto again;
 
        iio_unmark_sw_rb_in_use(&ring->buf);