[PATCH v2 07/19] dmaengine: dw-edma: Dispatch DONE interrupts by channel request

[Koichiro Den]

Handle the channel request first in the DONE interrupt path, then look
at the issued descriptor list only in the cases that need it.

This keeps the existing behavior, including the current STOP and PAUSE
handling when no issued descriptor is present.

No functional change intended.

Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
---
Changes in v2:
  - Limit this patch to request dispatch with no functional change;
    move LL progress and empty-issued-list handling to later patches.

 drivers/dma/dw-edma/dw-edma-core.c | 60 +++++++++++++++---------------
 1 file changed, 31 insertions(+), 29 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 29f78405e9fb..fa104af4146e 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -682,41 +682,43 @@ 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_end = chan->ll_head;
-			}
-
-			if (chan->request == EDMA_REQ_PAUSE) {
-				chan->request = EDMA_REQ_NONE;
-				chan->status = EDMA_ST_PAUSE;
-				break;
-			}
-
-			/* Continue transferring if there are remaining chunks or issued requests.
-			 */
-			chan->status = dw_edma_start_transfer(chan) ? EDMA_ST_BUSY : EDMA_ST_IDLE;
+	switch (chan->request) {
+	case EDMA_REQ_NONE:
+	case EDMA_REQ_PAUSE:
+		vd = vchan_next_desc(&chan->vc);
+		if (!vd)
 			break;
 
-		case EDMA_REQ_STOP:
-			dw_edma_terminate_all_descs(chan);
+		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_end = chan->ll_head;
+		}
+
+		if (chan->request == EDMA_REQ_PAUSE) {
 			chan->request = EDMA_REQ_NONE;
-			chan->status = EDMA_ST_IDLE;
+			chan->status = EDMA_ST_PAUSE;
 			break;
+		}
 
-		default:
+		chan->status = dw_edma_start_transfer(chan) ? EDMA_ST_BUSY : EDMA_ST_IDLE;
+		break;
+
+	case EDMA_REQ_STOP:
+		vd = vchan_next_desc(&chan->vc);
+		if (!vd)
 			break;
-		}
+
+		dw_edma_terminate_all_descs(chan);
+		chan->request = EDMA_REQ_NONE;
+		chan->status = EDMA_ST_IDLE;
+		break;
+
+	default:
+		break;
 	}
 	spin_unlock_irqrestore(&chan->vc.lock, flags);
 }
-- 
2.51.0