From: "John W. Linville" <linville@tuxdriver.com>
Just curious...wanna try this patch I got from Intel? I think it
may help...
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
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 2005-03-06 19:25:00.000000000 -0800
+++ 25-akpm/drivers/net/e100.c 2005-03-06 19:25:01.000000000 -0800
@@ -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;
_