[media] mem2mem_testdev: return pending buffers in stop_streaming()

To keep the vb2 buffer administration in balance stop_streaming() must
return any pending buffers to the vb2 framework.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/platform/mem2mem_testdev.c

@@ -768,10 +768,31 @@ static void m2mtest_buf_queue(struct vb2_buffer *vb)
 	v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vb);
 }
 
+static int m2mtest_stop_streaming(struct vb2_queue *q)
+{
+	struct m2mtest_ctx *ctx = vb2_get_drv_priv(q);
+	struct vb2_buffer *vb;
+	unsigned long flags;
+
+	for (;;) {
+		if (V4L2_TYPE_IS_OUTPUT(q->type))
+			vb = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
+		else
+			vb = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
+		if (vb == NULL)
+			return 0;
+		spin_lock_irqsave(&ctx->dev->irqlock, flags);
+		v4l2_m2m_buf_done(vb, VB2_BUF_STATE_ERROR);
+		spin_unlock_irqrestore(&ctx->dev->irqlock, flags);
+	}
+	return 0;
+}
+
 static struct vb2_ops m2mtest_qops = {
 	.queue_setup	 = m2mtest_queue_setup,
 	.buf_prepare	 = m2mtest_buf_prepare,
 	.buf_queue	 = m2mtest_buf_queue,
+	.stop_streaming  = m2mtest_stop_streaming,
 	.wait_prepare	 = vb2_ops_wait_prepare,
 	.wait_finish	 = vb2_ops_wait_finish,
 };