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lantiq/xrx200-net: fix "tx ring full" error by introducing second DMA TX channel

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With an own DMA TX channel for each network device (eth0 + eth1) there
won't be any "tx ring full" errors any more.

This patch also move the spinlocks to the channel level instead of locking
the whole xrx200_hw structure.

Signed-off-by: Martin Schiller <mschiller@tdt.de>
This commit is contained in:
Martin Schiller 2016-08-12 10:39:38 +02:00 committed by John Crispin
parent fca1eb349e
commit 8f02f7c7f8
1 changed files with 31 additions and 17 deletions
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48
target/linux/lantiq/patches-4.4/0025-NET-MIPS-lantiq-adds-xrx200-net.patch
View file

@ -209,7 +209,7 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+};
--- /dev/null
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -0,0 +1,1836 @@
@@ -0,0 +1,1850 @@
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
@ -276,6 +276,7 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+#define XRX200_DMA_IRQ INT_NUM_IM2_IRL0
+#define XRX200_DMA_RX 0
+#define XRX200_DMA_TX 1
+#define XRX200_DMA_TX_2 3
+#define XRX200_DMA_IS_TX(x) (x%2)
+#define XRX200_DMA_IS_RX(x) (!XRX200_DMA_IS_TX(x))
+
@ -424,6 +425,8 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+ struct napi_struct napi;
+ struct ltq_dma_channel dma;
+ struct sk_buff *skb[LTQ_DESC_NUM];
+
+ spinlock_t lock;
+};
+
+struct xrx200_hw {
@ -440,8 +443,6 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+ int port_map[XRX200_MAX_PORT];
+ unsigned short wan_map;
+
+ spinlock_t lock;
+
+ struct switch_dev swdev;
+};
+
@ -1078,14 +1079,14 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+ for (i = 0; i < XRX200_MAX_DMA; i++) {
+ if (!priv->hw->chan[i].dma.irq)
+ continue;
+ spin_lock_bh(&priv->hw->lock);
+ spin_lock_bh(&priv->hw->chan[i].lock);
+ if (!priv->hw->chan[i].refcount) {
+ if (XRX200_DMA_IS_RX(i))
+ napi_enable(&priv->hw->chan[i].napi);
+ ltq_dma_open(&priv->hw->chan[i].dma);
+ }
+ priv->hw->chan[i].refcount++;
+ spin_unlock_bh(&priv->hw->lock);
+ spin_unlock_bh(&priv->hw->chan[i].lock);
+ }
+ for (i = 0; i < priv->num_port; i++)
+ if (priv->port[i].phydev)
@ -1109,14 +1110,14 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+ for (i = 0; i < XRX200_MAX_DMA; i++) {
+ if (!priv->hw->chan[i].dma.irq)
+ continue;
+ spin_lock_bh(&priv->hw->lock);
+ spin_lock_bh(&priv->hw->chan[i].lock);
+ priv->hw->chan[i].refcount--;
+ if (!priv->hw->chan[i].refcount) {
+ if (XRX200_DMA_IS_RX(i))
+ napi_disable(&priv->hw->chan[i].napi);
+ ltq_dma_close(&priv->hw->chan[XRX200_DMA_RX].dma);
+ }
+ spin_unlock_bh(&priv->hw->lock);
+ spin_unlock_bh(&priv->hw->chan[i].lock);
+ }
+
+ return 0;
@ -1211,12 +1212,11 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+
+static void xrx200_tx_housekeeping(unsigned long ptr)
+{
+ struct xrx200_hw *hw = (struct xrx200_hw *) ptr;
+ struct xrx200_chan *ch = &hw->chan[XRX200_DMA_TX];
+ struct xrx200_chan *ch = (struct xrx200_chan *) ptr;
+ int pkts = 0;
+ int i;
+
+ spin_lock_bh(&hw->lock);
+ spin_lock_bh(&ch->lock);
+ ltq_dma_ack_irq(&ch->dma);
+ while ((ch->dma.desc_base[ch->tx_free].ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
+ struct sk_buff *skb = ch->skb[ch->tx_free];
@ -1230,7 +1230,7 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+ ch->tx_free %= LTQ_DESC_NUM;
+ }
+ ltq_dma_enable_irq(&ch->dma);
+ spin_unlock_bh(&hw->lock);
+ spin_unlock_bh(&ch->lock);
+
+ if (!pkts)
+ return;
@ -1259,14 +1259,20 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+static int xrx200_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct xrx200_priv *priv = netdev_priv(dev);
+ struct xrx200_chan *ch = &priv->hw->chan[XRX200_DMA_TX];
+ struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
+ struct xrx200_chan *ch;
+ struct ltq_dma_desc *desc;
+ u32 byte_offset;
+ int ret = NETDEV_TX_OK;
+ int len;
+#ifdef SW_ROUTING
+ u32 special_tag = (SPID_CPU_PORT << SPID_SHIFT) | DPID_ENABLE;
+#endif
+ if(priv->id)
+ ch = &priv->hw->chan[XRX200_DMA_TX_2];
+ else
+ ch = &priv->hw->chan[XRX200_DMA_TX];
+
+ desc = &ch->dma.desc_base[ch->dma.desc];
+
+ skb->dev = dev;
+ len = skb->len < ETH_ZLEN ? ETH_ZLEN : skb->len;
@ -1306,7 +1312,7 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+ /* dma needs to start on a 16 byte aligned address */
+ byte_offset = CPHYSADDR(skb->data) % 16;
+
+ spin_lock_bh(&priv->hw->lock);
+ spin_lock_bh(&ch->lock);
+ if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) || ch->skb[ch->dma.desc]) {
+ netdev_err(dev, "tx ring full\n");
+ netif_stop_queue(dev);
@ -1333,7 +1339,7 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+ priv->stats.tx_bytes+=len;
+
+out:
+ spin_unlock_bh(&priv->hw->lock);
+ spin_unlock_bh(&ch->lock);
+
+ return ret;
+}
@ -1365,11 +1371,16 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+ int irq = XRX200_DMA_IRQ + i;
+ struct xrx200_chan *ch = &hw->chan[i];
+
+ spin_lock_init(&ch->lock);
+
+ ch->idx = ch->dma.nr = i;
+
+ if (i == XRX200_DMA_TX) {
+ ltq_dma_alloc_tx(&ch->dma);
+ err = request_irq(irq, xrx200_dma_irq, 0, "vrx200_tx", hw);
+ } else if (i == XRX200_DMA_TX_2) {
+ ltq_dma_alloc_tx(&ch->dma);
+ err = request_irq(irq, xrx200_dma_irq, 0, "vrx200_tx_2", hw);
+ } else if (i == XRX200_DMA_RX) {
+ ltq_dma_alloc_rx(&ch->dma);
+ for (ch->dma.desc = 0; ch->dma.desc < LTQ_DESC_NUM;
@ -1383,6 +1394,8 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+
+ if (!err)
+ ch->dma.irq = irq;
+ else
+ pr_err("net-xrx200: failed to request irq %d\n", irq);
+ }
+
+ return err;
@ -1952,10 +1965,10 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+ }
+
+ /* bring up the dma engine and IP core */
+ spin_lock_init(&xrx200_hw.lock);
+ xrx200_dma_init(&xrx200_hw);
+ xrx200_hw_init(&xrx200_hw);
+ tasklet_init(&xrx200_hw.chan[XRX200_DMA_TX].tasklet, xrx200_tx_housekeeping, (u32) &xrx200_hw);
+ tasklet_init(&xrx200_hw.chan[XRX200_DMA_TX].tasklet, xrx200_tx_housekeeping, (u32) &xrx200_hw.chan[XRX200_DMA_TX]);
+ tasklet_init(&xrx200_hw.chan[XRX200_DMA_TX_2].tasklet, xrx200_tx_housekeeping, (u32) &xrx200_hw.chan[XRX200_DMA_TX_2]);
+
+ /* bring up the mdio bus */
+ mdio_np = of_find_compatible_node(pdev->dev.of_node, NULL,
@ -1989,6 +2002,7 @@ Subject: [PATCH 25/36] NET: MIPS: lantiq: adds xrx200-net
+ for (i = 0; i < xrx200_hw.num_devs; i++) {
+ xrx200_hw.chan[XRX200_DMA_RX].devs[i] = xrx200_hw.devs[i];
+ xrx200_hw.chan[XRX200_DMA_TX].devs[i] = xrx200_hw.devs[i];
+ xrx200_hw.chan[XRX200_DMA_TX_2].devs[i] = xrx200_hw.devs[i];
+ }
+
+ /* setup NAPI */