diff options
Diffstat (limited to 'target/linux')
| -rw-r--r-- | target/linux/ar7/patches-2.6.24/160-cpmac-rx-ring-use-eoq.diff | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/target/linux/ar7/patches-2.6.24/160-cpmac-rx-ring-use-eoq.diff b/target/linux/ar7/patches-2.6.24/160-cpmac-rx-ring-use-eoq.diff new file mode 100644 index 0000000000..47f7e6c989 --- /dev/null +++ b/target/linux/ar7/patches-2.6.24/160-cpmac-rx-ring-use-eoq.diff @@ -0,0 +1,178 @@ +--- linux-2.6.24.3/drivers/net/cpmac.c.orig 2008-03-10 23:59:56.000000000 +0000 ++++ linux-2.6.24.3/drivers/net/cpmac.c 2008-03-11 00:13:04.000000000 +0000 +@@ -187,6 +187,7 @@ + #define CPMAC_EOQ 0x1000 + struct sk_buff *skb; + struct cpmac_desc *next; ++ struct cpmac_desc *prev; + dma_addr_t mapping; + dma_addr_t data_mapping; + }; +@@ -242,6 +243,16 @@ + printk("\n"); + } + ++static void cpmac_dump_all_desc(struct net_device *dev) ++{ ++ struct cpmac_priv *priv = netdev_priv(dev); ++ struct cpmac_desc *dump = priv->rx_head; ++ do { ++ cpmac_dump_desc(dev, dump); ++ dump = dump->next; ++ } while (dump != priv->rx_head); ++} ++ + static void cpmac_dump_skb(struct net_device *dev, struct sk_buff *skb) + { + int i; +@@ -413,21 +424,40 @@ + static int cpmac_poll(struct napi_struct *napi, int budget) + { + struct sk_buff *skb; +- struct cpmac_desc *desc; +- int received = 0; ++ struct cpmac_desc *desc, *restart; + struct cpmac_priv *priv = container_of(napi, struct cpmac_priv, napi); ++ int received = 0, processed = 0; + + spin_lock(&priv->rx_lock); + if (unlikely(!priv->rx_head)) { + if (netif_msg_rx_err(priv) && net_ratelimit()) + printk(KERN_WARNING "%s: rx: polling, but no queue\n", + priv->dev->name); ++ spin_unlock(&priv->rx_lock); + netif_rx_complete(priv->dev, napi); + return 0; + } + + desc = priv->rx_head; ++ restart = NULL; + while (((desc->dataflags & CPMAC_OWN) == 0) && (received < budget)) { ++ processed++; ++ ++ if ((desc->dataflags & CPMAC_EOQ) != 0) { ++ /* The last update to eoq->hw_next didn't happen soon enough, and the ++ * receiver stopped here. Remember this descriptor so we can restart ++ * the receiver after freeing some space. ++ */ ++ if (unlikely(restart)) { ++ if (netif_msg_rx_err(priv)) ++ printk(KERN_ERR "%s: poll found a duplicate EOQ: %p and %p\n", ++ priv->dev->name, restart, desc); ++ goto fatal_error; ++ } ++ ++ restart = desc->next; ++ } ++ + skb = cpmac_rx_one(priv, desc); + if (likely(skb)) { + netif_receive_skb(skb); +@@ -436,19 +466,81 @@ + desc = desc->next; + } + ++ if (desc != priv->rx_head) { ++ /* We freed some buffers, but not the whole ring, add what we did free to the rx list */ ++ desc->prev->hw_next = (u32)0; ++ priv->rx_head->prev->hw_next = priv->rx_head->mapping; ++ } ++ ++ /* Optimization: If we did not actually process an EOQ (perhaps because of ++ * quota limits), check to see if the tail of the queue has EOQ set. We ++ * should immediately restart in that case so that the receiver can restart ++ * and run in parallel with more packet processing. This lets us handle slightly ++ * larger bursts before running out of ring space (assuming dev->weight < ring_size) ++ */ ++ if (!restart && ++ (priv->rx_head->prev->dataflags & (CPMAC_OWN|CPMAC_EOQ)) == CPMAC_EOQ && ++ (priv->rx_head->dataflags & CPMAC_OWN) != 0) { ++ /* reset EOQ so the poll loop (above) doesn't try to restart this when it ++ * eventually gets to this descriptor. ++ */ ++ priv->rx_head->prev->dataflags &= ~CPMAC_EOQ; ++ restart = priv->rx_head; ++ } ++ ++ if (restart) { ++ priv->dev->stats.rx_errors++; ++ priv->dev->stats.rx_fifo_errors++; ++ if (netif_msg_rx_err(priv) && net_ratelimit()) ++ printk(KERN_WARNING "%s: rx dma ring overrun\n", priv->dev->name); ++ ++ if (unlikely((restart->dataflags & CPMAC_OWN) == 0)) { ++ if (netif_msg_drv(priv)) ++ printk(KERN_ERR "%s: cpmac_poll is trying to restart rx from a descriptor that's not free: %p\n", ++ priv->dev->name, restart); ++ goto fatal_error; ++ } ++ ++ cpmac_write(priv->regs, CPMAC_RX_PTR(0), restart->mapping); ++ } ++ + priv->rx_head = desc; + spin_unlock(&priv->rx_lock); + if (unlikely(netif_msg_rx_status(priv))) + printk(KERN_DEBUG "%s: poll processed %d packets\n", + priv->dev->name, received); +- if (desc->dataflags & CPMAC_OWN) { ++ if (processed == 0) { ++ /* we ran out of packets to read, revert to interrupt-driven mode */ + netif_rx_complete(priv->dev, napi); +- cpmac_write(priv->regs, CPMAC_RX_PTR(0), (u32)desc->mapping); + cpmac_write(priv->regs, CPMAC_RX_INT_ENABLE, 1); + return 0; + } + + return 1; ++ ++fatal_error: ++ /* Something went horribly wrong. Reset hardware to try to recover rather than wedging. */ ++ ++ if (netif_msg_drv(priv)) { ++ printk(KERN_ERR "%s: cpmac_poll is confused. Resetting hardware\n", priv->dev->name); ++ cpmac_dump_all_desc(priv->dev); ++ printk(KERN_DEBUG "%s: RX_PTR(0)=0x%08x RX_ACK(0)=0x%08x\n", ++ priv->dev->name, ++ cpmac_read(priv->regs, CPMAC_RX_PTR(0)), ++ cpmac_read(priv->regs, CPMAC_RX_ACK(0))); ++ } ++ ++ spin_unlock(&priv->rx_lock); ++ netif_rx_complete(priv->dev, napi); ++ netif_stop_queue(priv->dev); ++ napi_disable(&priv->napi); ++ ++ atomic_inc(&priv->reset_pending); ++ cpmac_hw_stop(priv->dev); ++ if (!schedule_work(&priv->reset_work)) ++ atomic_dec(&priv->reset_pending); ++ return 0; ++ + } + + static int cpmac_start_xmit(struct sk_buff *skb, struct net_device *dev) +@@ -625,8 +717,10 @@ + desc->dataflags = CPMAC_OWN; + dev->stats.rx_dropped++; + } ++ desc->hw_next = desc->next->mapping; + desc = desc->next; + } ++ priv->rx_head->prev->hw_next = 0; + } + + static void cpmac_clear_tx(struct net_device *dev) +@@ -927,9 +1021,12 @@ + desc->buflen = CPMAC_SKB_SIZE; + desc->dataflags = CPMAC_OWN; + desc->next = &priv->rx_head[(i + 1) % priv->ring_size]; ++ desc->next->prev = desc; + desc->hw_next = (u32)desc->next->mapping; + } + ++ priv->rx_head->prev->hw_next = (u32)0; ++ + if ((res = request_irq(dev->irq, cpmac_irq, IRQF_SHARED, + dev->name, dev))) { + if (netif_msg_drv(priv)) |