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[PATCH 01/12] net-next: mediatek: fix DQL support

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The MTK ethernet core has 2 MACs both sitting on the same DMA ring. The
current code will assign the TX traffic of each MAC to its own DQL. This
results in the amount of data, that DQL says is in the queue incorrect. As
the data from multiple devices is infact enqueued. This makes any decision
based on these value non deterministic. Fix this by tracking all TX
traffic, regardless of the MAC it belongs to in the DQL of all devices
using the DMA.

Signed-off-by: John Crispin <john@phrozen.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |   33 ++++++++++++++++-----------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 41cdc0d..07674e5 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -641,7 +641,16 @@ static int mtk_tx_map(struct sk_buff *skb, struct net_device *dev,
 	WRITE_ONCE(itxd->txd3, (TX_DMA_SWC | TX_DMA_PLEN0(skb_headlen(skb)) |
 				(!nr_frags * TX_DMA_LS0)));
 
-	netdev_sent_queue(dev, skb->len);
+	/* we have a single DMA ring so BQL needs to be updated for all devices
+	 * sitting on this ring
+	 */
+	for (i = 0; i < MTK_MAC_COUNT; i++) {
+		if (!eth->netdev[i])
+			continue;
+
+		netdev_sent_queue(eth->netdev[i], skb->len);
+	}
+
 	skb_tx_timestamp(skb);
 
 	ring->next_free = mtk_qdma_phys_to_virt(ring, txd->txd2);
@@ -869,21 +878,18 @@ static int mtk_poll_tx(struct mtk_eth *eth, int budget, bool *tx_again)
 	struct mtk_tx_dma *desc;
 	struct sk_buff *skb;
 	struct mtk_tx_buf *tx_buf;
-	int total = 0, done[MTK_MAX_DEVS];
-	unsigned int bytes[MTK_MAX_DEVS];
+	int total = 0, done = 0;
+	unsigned int bytes = 0;
 	u32 cpu, dma;
 	static int condition;
 	int i;
 
-	memset(done, 0, sizeof(done));
-	memset(bytes, 0, sizeof(bytes));
-
 	cpu = mtk_r32(eth, MTK_QTX_CRX_PTR);
 	dma = mtk_r32(eth, MTK_QTX_DRX_PTR);
 
 	desc = mtk_qdma_phys_to_virt(ring, cpu);
 
-	while ((cpu != dma) && budget) {
+	while ((cpu != dma) && done < budget) {
 		u32 next_cpu = desc->txd2;
 		int mac;
 
@@ -903,9 +909,8 @@ static int mtk_poll_tx(struct mtk_eth *eth, int budget, bool *tx_again)
 		}
 
 		if (skb != (struct sk_buff *)MTK_DMA_DUMMY_DESC) {
-			bytes[mac] += skb->len;
-			done[mac]++;
-			budget--;
+			bytes += skb->len;
+			done++;
 		}
 		mtk_tx_unmap(eth->dev, tx_buf);
 
@@ -918,11 +923,13 @@ static int mtk_poll_tx(struct mtk_eth *eth, int budget, bool *tx_again)
 
 	mtk_w32(eth, cpu, MTK_QTX_CRX_PTR);
 
+	/* we have a single DMA ring so BQL needs to be updated for all devices
+	 * sitting on this ring
+	 */
 	for (i = 0; i < MTK_MAC_COUNT; i++) {
-		if (!eth->netdev[i] || !done[i])
+		if (!eth->netdev[i])
 			continue;
-		netdev_completed_queue(eth->netdev[i], done[i], bytes[i]);
-		total += done[i];
+		netdev_completed_queue(eth->netdev[i], done, bytes);
 	}
 
 	/* read hw index again make sure no new tx packet */
-- 
1.7.10.4

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[PATCH 00/12] net-next: mediatek: bug fixes and tx stall fixes John Crispin <john@phrozen.org> - 2016-05-05 11:30 +0200
  [PATCH 01/12] net-next: mediatek: fix DQL support John Crispin <john@phrozen.org> - 2016-05-05 11:30 +0200
  [PATCH 09/12] net-next: mediatek: increase watchdog_timeo John Crispin <john@phrozen.org> - 2016-05-05 11:30 +0200
  [PATCH 06/12] net-next: mediatek: add next data pointer coherency protection John Crispin <john@phrozen.org> - 2016-05-05 11:30 +0200
  [PATCH 04/12] net-next: mediatek: invalid buffer lookup in mtk_tx_map() John Crispin <john@phrozen.org> - 2016-05-05 11:40 +0200
  [PATCH 08/12] net-next: mediatek: fix threshold value John Crispin <john@phrozen.org> - 2016-05-05 11:40 +0200
  [PATCH 03/12] net-next: mediatek: fix missing free of scratch memory John Crispin <john@phrozen.org> - 2016-05-05 11:40 +0200
  [PATCH 02/12] net-next: mediatek: add missing return code check John Crispin <john@phrozen.org> - 2016-05-05 11:40 +0200
  [PATCH 12/12] net-next: mediatek: remove superfluous queue wake up call John Crispin <john@phrozen.org> - 2016-05-05 12:00 +0200
  [PATCH 10/12] net-next: mediatek: fix off by one in the TX ring allocation John Crispin <john@phrozen.org> - 2016-05-05 12:00 +0200
  [PATCH 11/12] net-next: mediatek: only wake the queue if it is stopped John Crispin <john@phrozen.org> - 2016-05-05 12:00 +0200
  Re: [PATCH 00/12] net-next: mediatek: bug fixes and tx stall fixes Andrew Lunn <andrew@lunn.ch> - 2016-05-05 14:30 +0200

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