From: "John W. Linville" Just curious...wanna try this patch I got from Intel? I think it may help... Signed-off-by: Andrew Morton --- 25-akpm/drivers/net/e100.c | 69 +++++++++++++++++++++++++++++++++++++-------- 1 files changed, 57 insertions(+), 12 deletions(-) diff -puN drivers/net/e100.c~e100-napi-fixes drivers/net/e100.c --- 25/drivers/net/e100.c~e100-napi-fixes Tue Mar 15 14:19:53 2005 +++ 25-akpm/drivers/net/e100.c Tue Mar 15 14:19:53 2005 @@ -269,6 +269,12 @@ enum scb_status { rus_mask = 0x3C, }; +enum ru_state { + RU_SUSPENDED = 0, + RU_RUNNING = 1, + RU_UNINITIALIZED = -1, +}; + enum scb_stat_ack { stat_ack_not_ours = 0x00, stat_ack_sw_gen = 0x04, @@ -510,7 +516,7 @@ struct nic { struct rx *rx_to_use; struct rx *rx_to_clean; struct rfd blank_rfd; - int ru_running; + enum ru_state ru_running; spinlock_t cb_lock ____cacheline_aligned; spinlock_t cmd_lock; @@ -1415,12 +1421,18 @@ static int e100_alloc_cbs(struct nic *ni return 0; } -static inline void e100_start_receiver(struct nic *nic) +static inline void e100_start_receiver(struct nic *nic, struct rx *rx) { + if(!nic->rxs) return; + if(RU_SUSPENDED != nic->ru_running) return; + + /* handle init time starts */ + if(!rx) rx = nic->rxs; + /* (Re)start RU if suspended or idle and RFA is non-NULL */ - if(!nic->ru_running && nic->rx_to_clean->skb) { - e100_exec_cmd(nic, ruc_start, nic->rx_to_clean->dma_addr); - nic->ru_running = 1; + if(rx->skb) { + e100_exec_cmd(nic, ruc_start, rx->dma_addr); + nic->ru_running = RU_RUNNING; } } @@ -1471,7 +1483,7 @@ static inline int e100_rx_indicate(struc /* If data isn't ready, nothing to indicate */ if(unlikely(!(rfd_status & cb_complete))) - return -EAGAIN; + return -ENODATA; /* Get actual data size */ actual_size = le16_to_cpu(rfd->actual_size) & 0x3FFF; @@ -1482,6 +1494,10 @@ static inline int e100_rx_indicate(struc pci_unmap_single(nic->pdev, rx->dma_addr, RFD_BUF_LEN, PCI_DMA_FROMDEVICE); + /* this allows for a fast restart without re-enabling interrupts */ + if(le16_to_cpu(rfd->command) & cb_el) + nic->ru_running = RU_SUSPENDED; + /* Pull off the RFD and put the actual data (minus eth hdr) */ skb_reserve(skb, sizeof(struct rfd)); skb_put(skb, actual_size); @@ -1514,20 +1530,45 @@ static inline void e100_rx_clean(struct unsigned int work_to_do) { struct rx *rx; + int restart_required = 0; + struct rx *rx_to_start = NULL; + + /* are we already rnr? then pay attention!!! this ensures that + * the state machine progression never allows a start with a + * partially cleaned list, avoiding a race between hardware + * and rx_to_clean when in NAPI mode */ + if(RU_SUSPENDED == nic->ru_running) + restart_required = 1; /* Indicate newly arrived packets */ for(rx = nic->rx_to_clean; rx->skb; rx = nic->rx_to_clean = rx->next) { - if(e100_rx_indicate(nic, rx, work_done, work_to_do)) + int err = e100_rx_indicate(nic, rx, work_done, work_to_do); + if(-EAGAIN == err) { + /* hit quota so have more work to do, restart once + * cleanup is complete */ + restart_required = 0; + break; + } else if(-ENODATA == err) break; /* No more to clean */ } + /* save our starting point as the place we'll restart the receiver */ + if(restart_required) + rx_to_start = nic->rx_to_clean; + /* Alloc new skbs to refill list */ for(rx = nic->rx_to_use; !rx->skb; rx = nic->rx_to_use = rx->next) { if(unlikely(e100_rx_alloc_skb(nic, rx))) break; /* Better luck next time (see watchdog) */ } - e100_start_receiver(nic); + if(restart_required) { + // ack the rnr? + writeb(stat_ack_rnr, &nic->csr->scb.stat_ack); + e100_start_receiver(nic, rx_to_start); + if(work_done) + (*work_done)++; + } } static void e100_rx_clean_list(struct nic *nic) @@ -1535,6 +1576,8 @@ static void e100_rx_clean_list(struct ni struct rx *rx; unsigned int i, count = nic->params.rfds.count; + nic->ru_running = RU_UNINITIALIZED; + if(nic->rxs) { for(rx = nic->rxs, i = 0; i < count; rx++, i++) { if(rx->skb) { @@ -1548,7 +1591,6 @@ static void e100_rx_clean_list(struct ni } nic->rx_to_use = nic->rx_to_clean = NULL; - nic->ru_running = 0; } static int e100_rx_alloc_list(struct nic *nic) @@ -1557,6 +1599,7 @@ static int e100_rx_alloc_list(struct nic unsigned int i, count = nic->params.rfds.count; nic->rx_to_use = nic->rx_to_clean = NULL; + nic->ru_running = RU_UNINITIALIZED; if(!(nic->rxs = kmalloc(sizeof(struct rx) * count, GFP_ATOMIC))) return -ENOMEM; @@ -1572,6 +1615,7 @@ static int e100_rx_alloc_list(struct nic } nic->rx_to_use = nic->rx_to_clean = nic->rxs; + nic->ru_running = RU_SUSPENDED; return 0; } @@ -1593,7 +1637,7 @@ static irqreturn_t e100_intr(int irq, vo /* We hit Receive No Resource (RNR); restart RU after cleaning */ if(stat_ack & stat_ack_rnr) - nic->ru_running = 0; + nic->ru_running = RU_SUSPENDED; e100_disable_irq(nic); netif_rx_schedule(netdev); @@ -1609,6 +1653,7 @@ static int e100_poll(struct net_device * int tx_cleaned; e100_rx_clean(nic, &work_done, work_to_do); + // should we be quota on tx? tx_cleaned = e100_tx_clean(nic); /* If no Rx and Tx cleanup work was done, exit polling mode. */ @@ -1683,7 +1728,7 @@ static int e100_up(struct nic *nic) if((err = e100_hw_init(nic))) goto err_clean_cbs; e100_set_multicast_list(nic->netdev); - e100_start_receiver(nic); + e100_start_receiver(nic, 0); mod_timer(&nic->watchdog, jiffies); if((err = request_irq(nic->pdev->irq, e100_intr, SA_SHIRQ, nic->netdev->name, nic->netdev))) @@ -1749,7 +1794,7 @@ static int e100_loopback_test(struct nic mdio_write(nic->netdev, nic->mii.phy_id, MII_BMCR, BMCR_LOOPBACK); - e100_start_receiver(nic); + e100_start_receiver(nic, 0); if(!(skb = dev_alloc_skb(ETH_DATA_LEN))) { err = -ENOMEM; _