diff options
Diffstat (limited to 'drivers/net/ethernet/sun/sunvnet.c')
| -rw-r--r-- | drivers/net/ethernet/sun/sunvnet.c | 45 |
1 files changed, 40 insertions, 5 deletions
diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c index d813bfb1a84..f67539650c3 100644 --- a/drivers/net/ethernet/sun/sunvnet.c +++ b/drivers/net/ethernet/sun/sunvnet.c @@ -32,6 +32,11 @@ MODULE_DESCRIPTION("Sun LDOM virtual network driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_MODULE_VERSION); +/* Heuristic for the number of times to exponentially backoff and + * retry sending an LDC trigger when EAGAIN is encountered + */ +#define VNET_MAX_RETRIES 10 + /* Ordered from largest major to lowest */ static struct vio_version vnet_versions[] = { { .major = 1, .minor = 0 }, @@ -260,6 +265,7 @@ static int vnet_send_ack(struct vnet_port *port, struct vio_dring_state *dr, .state = vio_dring_state, }; int err, delay; + int retries = 0; hdr.seq = dr->snd_nxt; delay = 1; @@ -272,6 +278,13 @@ static int vnet_send_ack(struct vnet_port *port, struct vio_dring_state *dr, udelay(delay); if ((delay <<= 1) > 128) delay = 128; + if (retries++ > VNET_MAX_RETRIES) { + pr_info("ECONNRESET %x:%x:%x:%x:%x:%x\n", + port->raddr[0], port->raddr[1], + port->raddr[2], port->raddr[3], + port->raddr[4], port->raddr[5]); + err = -ECONNRESET; + } } while (err == -EAGAIN); return err; @@ -337,14 +350,17 @@ static int vnet_walk_rx_one(struct vnet_port *port, if (IS_ERR(desc)) return PTR_ERR(desc); + if (desc->hdr.state != VIO_DESC_READY) + return 1; + + rmb(); + viodbg(DATA, "vio_walk_rx_one desc[%02x:%02x:%08x:%08x:%llx:%llx]\n", desc->hdr.state, desc->hdr.ack, desc->size, desc->ncookies, desc->cookies[0].cookie_addr, desc->cookies[0].cookie_size); - if (desc->hdr.state != VIO_DESC_READY) - return 1; err = vnet_rx_one(port, desc->size, desc->cookies, desc->ncookies); if (err == -ECONNRESET) return err; @@ -475,8 +491,9 @@ static int handle_mcast(struct vnet_port *port, void *msgbuf) return 0; } -static void maybe_tx_wakeup(struct vnet *vp) +static void maybe_tx_wakeup(unsigned long param) { + struct vnet *vp = (struct vnet *)param; struct net_device *dev = vp->dev; netif_tx_lock(dev); @@ -573,8 +590,13 @@ static void vnet_event(void *arg, int event) break; } spin_unlock(&vio->lock); + /* Kick off a tasklet to wake the queue. We cannot call + * maybe_tx_wakeup directly here because we could deadlock on + * netif_tx_lock() with dev_watchdog() + */ if (unlikely(tx_wakeup && err != -ECONNRESET)) - maybe_tx_wakeup(port->vp); + tasklet_schedule(&port->vp->vnet_tx_wakeup); + local_irq_restore(flags); } @@ -593,6 +615,7 @@ static int __vnet_tx_trigger(struct vnet_port *port) .end_idx = (u32) -1, }; int err, delay; + int retries = 0; hdr.seq = dr->snd_nxt; delay = 1; @@ -605,6 +628,8 @@ static int __vnet_tx_trigger(struct vnet_port *port) udelay(delay); if ((delay <<= 1) > 128) delay = 128; + if (retries++ > VNET_MAX_RETRIES) + break; } while (err == -EAGAIN); return err; @@ -691,7 +716,15 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev) memset(tx_buf+VNET_PACKET_SKIP+skb->len, 0, len - skb->len); } - d->hdr.ack = VIO_ACK_ENABLE; + /* We don't rely on the ACKs to free the skb in vnet_start_xmit(), + * thus it is safe to not set VIO_ACK_ENABLE for each transmission: + * the protocol itself does not require it as long as the peer + * sends a VIO_SUBTYPE_ACK for VIO_DRING_STOPPED. + * + * An ACK for every packet in the ring is expensive as the + * sending of LDC messages is slow and affects performance. + */ + d->hdr.ack = VIO_ACK_DISABLE; d->size = len; d->ncookies = port->tx_bufs[dr->prod].ncookies; for (i = 0; i < d->ncookies; i++) @@ -1046,6 +1079,7 @@ static struct vnet *vnet_new(const u64 *local_mac) vp = netdev_priv(dev); spin_lock_init(&vp->lock); + tasklet_init(&vp->vnet_tx_wakeup, maybe_tx_wakeup, (unsigned long)vp); vp->dev = dev; INIT_LIST_HEAD(&vp->port_list); @@ -1105,6 +1139,7 @@ static void vnet_cleanup(void) vp = list_first_entry(&vnet_list, struct vnet, list); list_del(&vp->list); dev = vp->dev; + tasklet_kill(&vp->vnet_tx_wakeup); /* vio_unregister_driver() should have cleaned up port_list */ BUG_ON(!list_empty(&vp->port_list)); unregister_netdev(dev); |