[PATCH 5/5] net: ethernet: mediatek: enable rx path by aggregrating more skbs

[Sean Wang <sean.wang@mediatek.com>]

The patch adds support for aggregrating more skbs feed into NAPI in
order to get benifits from generic receive offload (GRO) by peeking
at the RX ring status and moving more packet right before returning
from NAPI rx handler if NAPI budgets is still available.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |   15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 53e24c1..742b9ec 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -902,9 +902,6 @@ release_desc:
 	wmb();
 	mtk_w32(eth, ring->calc_idx, MTK_QRX_CRX_IDX0);
 
-	if (done < budget)
-		mtk_w32(eth, MTK_RX_DONE_INT, MTK_QMTK_INT_STATUS);
-
 	return done;
 }
 
@@ -1023,8 +1020,10 @@ static int mtk_napi_rx(struct napi_struct *napi, int budget)
 	struct mtk_eth *eth = container_of(napi, struct mtk_eth, rx_napi);
 	u32 status, mask;
 	int rx_done = 0;
+	int remain_budget = budget;
 
 	mtk_handle_status_irq(eth);
+poll_again:
 	mtk_w32(eth, MTK_RX_DONE_INT, MTK_QMTK_INT_STATUS);
 	rx_done = mtk_poll_rx(napi, budget, eth);
 
@@ -1035,14 +1034,14 @@ static int mtk_napi_rx(struct napi_struct *napi, int budget)
 			 "done rx %d, intr 0x%08x/0x%x\n",
 			 rx_done, status, mask);
 	}
-
-	if (rx_done == budget)
+	if (rx_done == remain_budget)
 		return budget;
 
 	status = mtk_r32(eth, MTK_QMTK_INT_STATUS);
-	if (status & MTK_RX_DONE_INT)
-		return budget;
-
+	if (status & MTK_RX_DONE_INT) {
+		remain_budget -= rx_done;
+		goto poll_again;
+	}
 	napi_complete(napi);
 	mtk_irq_enable(eth, MTK_RX_DONE_INT);
 
-- 
1.7.9.5