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 },
.state = vio_dring_state,
};
int err, delay;
+ int retries = 0;
hdr.seq = dr->snd_nxt;
delay = 1;
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;
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;
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);
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);
}
.end_idx = (u32) -1,
};
int err, delay;
+ int retries = 0;
hdr.seq = dr->snd_nxt;
delay = 1;
udelay(delay);
if ((delay <<= 1) > 128)
delay = 128;
+ if (retries++ > VNET_MAX_RETRIES)
+ break;
} while (err == -EAGAIN);
return err;
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++)
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);
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);