dmaengine: rcar-dmac: Fix residue reporting for pending descriptors

	struct rcar_dmac_desc *desc = chan->desc.running;

	struct rcar_dmac_xfer_chunk *running = NULL;

	struct rcar_dmac_xfer_chunk *chunk;

	enum dma_status status;

	unsigned int residue = 0;

	unsigned int dptr = 0;

	if (!desc)

		return 0;

	/*

	 * If the cookie corresponds to a descriptor that has been completed

	 * there is no residue. The same check has already been performed by the

	 * caller but without holding the channel lock, so the descriptor could

	 * now be complete.

	 */

	status = dma_cookie_status(&chan->chan, cookie, NULL);

	if (status == DMA_COMPLETE)

		return 0;

	/*

	 * If the cookie doesn't correspond to the currently running transfer

	 * then the descriptor hasn't been processed yet, and the residue is

	 * equal to the full descriptor size.

	 */

	if (cookie != desc->async_tx.cookie)

	if (cookie != desc->async_tx.cookie) {

		list_for_each_entry(desc, &chan->desc.pending, node) {

			if (cookie == desc->async_tx.cookie)

				return desc->size;

		}

		list_for_each_entry(desc, &chan->desc.active, node) {

			if (cookie == desc->async_tx.cookie)

				return desc->size;

		}

		/*

		 * No descriptor found for the cookie, there's thus no residue.

		 * This shouldn't happen if the calling driver passes a correct

		 * cookie value.

		 */

		WARN(1, "No descriptor for cookie!");

		return 0;

	}

	/*

	 * In descriptor mode the descriptor running pointer is not maintained