Linux-libre 4.2-gnu

1 files changed, 37 insertions, 1 deletions

diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index 73824a5ad..dc853e57f 100644
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -427,6 +427,25 @@ int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
 
 /**
+ * v4l2_m2m_prepare_buf() - prepare a source or destination buffer, depending on
+ * the type
+ */
+int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+			 struct v4l2_buffer *buf)
+{
+	struct vb2_queue *vq;
+	int ret;
+
+	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
+	ret = vb2_prepare_buf(vq, buf);
+	if (!ret)
+		v4l2_m2m_try_schedule(m2m_ctx);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_prepare_buf);
+
+/**
  * v4l2_m2m_create_bufs() - create a source or destination buffer, depending
  * on the type
  */
@@ -564,8 +583,16 @@ unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 
 	if (list_empty(&src_q->done_list))
 		poll_wait(file, &src_q->done_wq, wait);
-	if (list_empty(&dst_q->done_list))
+	if (list_empty(&dst_q->done_list)) {
+		/*
+		 * If the last buffer was dequeued from the capture queue,
+		 * return immediately. DQBUF will return -EPIPE.
+		 */
+		if (dst_q->last_buffer_dequeued)
+			return rc | POLLIN | POLLRDNORM;
+
 		poll_wait(file, &dst_q->done_wq, wait);
+	}
 
 	if (m2m_ctx->m2m_dev->m2m_ops->lock)
 		m2m_ctx->m2m_dev->m2m_ops->lock(m2m_ctx->priv);
@@ -803,6 +830,15 @@ int v4l2_m2m_ioctl_dqbuf(struct file *file, void *priv,
 }
 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_dqbuf);
 
+int v4l2_m2m_ioctl_prepare_buf(struct file *file, void *priv,
+			       struct v4l2_buffer *buf)
+{
+	struct v4l2_fh *fh = file->private_data;
+
+	return v4l2_m2m_prepare_buf(file, fh->m2m_ctx, buf);
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_prepare_buf);
+
 int v4l2_m2m_ioctl_expbuf(struct file *file, void *priv,
 				struct v4l2_exportbuffer *eb)
 {