Hi Gustavo,

 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
 				       dma->direction, DMA_PREP_INTERRUPT);
 
+	if (!desc) {
+		dev_err(&sdd->master->dev,
+			"%s:dmaengine_prep_slave_sg Failed\n", __func__);
+		return;
+	}
+

I'm sorry, I would nack this patch for now. There was a smilar I
sent before, but, as Krzysztof said, this needs more testing and
a proper solution.

That's anyway in my todo list.

Thanks,
Andi