[media] marvell-cam: ensure that the camera stops when requested

The controller stop/restart logic could possibly restart DMA after the
driver things things have stopped, with suitably ugly results.  Make sure
that we only restart the hardware if we're supposed to be streaming.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/marvell-ccic/mcam-core.c

@@ -555,6 +555,11 @@ static void mcam_dma_sg_done(struct mcam_camera *cam, int frame)
 {
 	struct mcam_vb_buffer *buf = cam->vb_bufs[0];
 
+	/*
+	 * If we're no longer supposed to be streaming, don't do anything.
+	 */
+	if (cam->state != S_STREAMING)
+		return;
 	/*
 	 * Very Bad Not Good Things happen if you don't clear
 	 * C1_DESC_ENA before making any descriptor changes.
@@ -922,7 +927,7 @@ static void mcam_vb_buf_queue(struct vb2_buffer *vb)
 	spin_lock_irqsave(&cam->dev_lock, flags);
 	start = (cam->state == S_BUFWAIT) && !list_empty(&cam->buffers);
 	list_add(&mvb->queue, &cam->buffers);
-	if (test_bit(CF_SG_RESTART, &cam->flags))
+	if (cam->state == S_STREAMING && test_bit(CF_SG_RESTART, &cam->flags))
 		mcam_sg_restart(cam);
 	spin_unlock_irqrestore(&cam->dev_lock, flags);
 	if (start)