[PATCH v4 06/24] dmaengine: dw-edma: Dispatch DONE interrupts by channel request

[Koichiro Den]

Prepare for a later patch that reclaims LL progress before request handling
and can remove the last issued descriptor. Move the request switch outside
the common descriptor check.

Keep the existing per-request descriptor checks for now. That later patch
removes them when STOP/PAUSE handling becomes independent of the descriptor
list.

No functional change.

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
---
Changes in v4:
  - Clarify that descriptor-independent STOP/PAUSE handling is added with
    LL progress reclamation later, not by this prep patch. (Sashiko)

 drivers/dma/dw-edma/dw-edma-core.c | 56 ++++++++++++++++--------------
 1 file changed, 29 insertions(+), 27 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 6e7d1f7c20f9..b419ff2becf9 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -697,39 +697,41 @@ static void dw_edma_done_interrupt(struct dw_edma_chan *chan)
 		return;
 	}
 
-	vd = vchan_next_desc(&chan->vc);
-	if (vd) {
-		switch (chan->request) {
-		case EDMA_REQ_NONE:
-		case EDMA_REQ_PAUSE:
-			desc = vd2dw_edma_desc(vd);
-			if (desc->start_burst >= desc->nburst) {
-				dw_hdma_set_callback_result(vd,
-							    DMA_TRANS_NOERROR);
-				list_del(&vd->node);
-				vchan_cookie_complete(vd);
-				if (!chan->non_ll)
-					chan->ll_done = chan->ll_head;
-			}
+	switch (chan->request) {
+	case EDMA_REQ_NONE:
+	case EDMA_REQ_PAUSE:
+		vd = vchan_next_desc(&chan->vc);
+		if (!vd)
+			break;
 
-			if (chan->request == EDMA_REQ_PAUSE) {
-				chan->request = EDMA_REQ_NONE;
-				chan->status = EDMA_ST_PAUSE;
-				break;
-			}
+		desc = vd2dw_edma_desc(vd);
+		if (desc->start_burst >= desc->nburst) {
+			dw_hdma_set_callback_result(vd, DMA_TRANS_NOERROR);
+			list_del(&vd->node);
+			vchan_cookie_complete(vd);
+			if (!chan->non_ll)
+				chan->ll_done = chan->ll_head;
+		}
 
-			/* Continue transferring if there are remaining chunks or issued requests.
-			 */
-			chan->status = dw_edma_start_transfer(chan) ? EDMA_ST_BUSY : EDMA_ST_IDLE;
+		if (chan->request == EDMA_REQ_PAUSE) {
+			chan->request = EDMA_REQ_NONE;
+			chan->status = EDMA_ST_PAUSE;
 			break;
+		}
 
-		case EDMA_REQ_STOP:
-			dw_edma_finish_termination(chan);
-			break;
+		chan->status = dw_edma_start_transfer(chan) ? EDMA_ST_BUSY : EDMA_ST_IDLE;
+		break;
 
-		default:
+	case EDMA_REQ_STOP:
+		vd = vchan_next_desc(&chan->vc);
+		if (!vd)
 			break;
-		}
+
+		dw_edma_finish_termination(chan);
+		break;
+
+	default:
+		break;
 	}
 	spin_unlock_irqrestore(&chan->vc.lock, flags);
 }
-- 
2.51.0