[PATCH 1/4] dmaengine: virt-dma: store result on dma descriptor

[Alexandru Ardelean <alexandru.ardelean@analog.com>]

This allows each virtual channel to store information about each transfer
that completed, i.e. which transfer succeeded (or which failed) and if
there was any residue data on each (completed) transfer.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
 drivers/dma/virt-dma.c | 4 ++--
 drivers/dma/virt-dma.h | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/virt-dma.c b/drivers/dma/virt-dma.c
index 88ad8ed2a8d6..bf560a20c8a8 100644
--- a/drivers/dma/virt-dma.c
+++ b/drivers/dma/virt-dma.c
@@ -101,7 +101,7 @@ static void vchan_complete(unsigned long arg)
 	}
 	spin_unlock_irq(&vc->lock);
 
-	dmaengine_desc_callback_invoke(&cb, NULL);
+	dmaengine_desc_callback_invoke(&cb, &vd->tx_result);
 
 	list_for_each_entry_safe(vd, _vd, &head, node) {
 		dmaengine_desc_get_callback(&vd->tx, &cb);
@@ -109,7 +109,7 @@ static void vchan_complete(unsigned long arg)
 		list_del(&vd->node);
 		vchan_vdesc_fini(vd);
 
-		dmaengine_desc_callback_invoke(&cb, NULL);
+		dmaengine_desc_callback_invoke(&cb, &vd->tx_result);
 	}
 }
 
diff --git a/drivers/dma/virt-dma.h b/drivers/dma/virt-dma.h
index b09b75ab0751..eb767c583b7e 100644
--- a/drivers/dma/virt-dma.h
+++ b/drivers/dma/virt-dma.h
@@ -17,6 +17,7 @@
 
 struct virt_dma_desc {
 	struct dma_async_tx_descriptor tx;
+	struct dmaengine_result tx_result;
 	/* protected by vc.lock */
 	struct list_head node;
 };
@@ -65,6 +66,9 @@ static inline struct dma_async_tx_descriptor *vchan_tx_prep(struct virt_dma_chan
 	vd->tx.tx_submit = vchan_tx_submit;
 	vd->tx.desc_free = vchan_tx_desc_free;
 
+	vd->tx_result.result = DMA_TRANS_NOERROR;
+	vd->tx_result.residue = 0;
+
 	spin_lock_irqsave(&vc->lock, flags);
 	list_add_tail(&vd->node, &vc->desc_allocated);
 	spin_unlock_irqrestore(&vc->lock, flags);
-- 
2.20.1