V4L/DVB (8772): cx18: Convert cx18_queue buffers member to atomic_t

cx18: Convert cx18_queue buffers member to atomic_t.  This allows safe
concurrent access to check if a queue has data without having to acquire the
queue spinlock.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/media/video/cx18/cx18-ioctl.c b/drivers/media/video/cx18/cx18-ioctl.c
index a7f839631d6a..5325c7aacaf3 100644
--- a/drivers/media/video/cx18/cx18-ioctl.c
+++ b/drivers/media/video/cx18/cx18-ioctl.c
@@ -731,7 +731,8 @@ static int cx18_log_status(struct file *file, void *fh)
                         continue;
                 CX18_INFO("Stream %s: status 0x%04lx, %d%% of %d KiB (%d buffers) in use\n",
                           s->name, s->s_flags,
-                          (s->buffers - s->q_free.buffers) * 100 / s->buffers,
+                          (s->buffers - atomic_read(&s->q_free.buffers))
+                                * 100 / s->buffers,
                           (s->buffers * s->buf_size) / 1024, s->buffers);
         }
         CX18_INFO("Read MPEG/VBI: %lld/%lld bytes\n",