static int wwan_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct wwan_private *wwan_ptr = netdev_priv(dev);
unsigned long flags;
int ret = 0;
if (netif_queue_stopped(dev)) {
pr_err("[%s]fatal: wwan_xmit called when netif_queue stopped\n",
dev->name);
return 0;
}
ret = ipa_rm_inactivity_timer_request_resource(
ipa_rm_resource_by_ch_id[wwan_ptr->ch_id]);
if (ret == -EINPROGRESS) {
netif_stop_queue(dev);
return NETDEV_TX_BUSY;
}
if (ret) {
pr_err("[%s] fatal: ipa rm timer request resource failed %d\n",
dev->name, ret);
return -EFAULT;
}
ret = wwan_send_packet(skb, dev);
if (ret == -EPERM) {
ret = NETDEV_TX_BUSY;
goto exit;
}
if (ret == -EFAULT) {
netif_carrier_off(dev);
dev_kfree_skb_any(skb);
ret = 0;
goto exit;
}
if (ret == -EAGAIN) {
netif_stop_queue(dev);
ret = NETDEV_TX_BUSY;
goto exit;
}
spin_lock_irqsave(&wwan_ptr->lock, flags);
if (a2_mux_is_ch_full(a2_mux_lcid_by_ch_id[wwan_ptr->ch_id])) {
netif_stop_queue(dev);
pr_debug("%s: High WM hit, stopping queue=%p\n",
__func__, skb);
}
spin_unlock_irqrestore(&wwan_ptr->lock, flags);
return ret;
exit:
ipa_rm_inactivity_timer_release_resource(
ipa_rm_resource_by_ch_id[wwan_ptr->ch_id]);
return ret;
}
/**
* wwan_xmit() - Transmits an skb. In charge of asking IPA
* RM needed resources. In case that IPA RM is not ready, then
* the skb is saved for tranmitting as soon as IPA RM resources
* are granted.
*
* @skb: skb to be transmitted
* @dev: network device
*
* Return codes:
* 0: success
* NETDEV_TX_BUSY: Error while transmitting the skb. Try again
* later
* -EFAULT: Error while transmitting the skb
*/
static int wwan_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct wwan_private *wwan_ptr = netdev_priv(dev);
unsigned long flags;
int ret = 0;
if (netif_queue_stopped(dev)) {
pr_err("[%s]fatal: wwan_xmit called when netif_queue stopped\n",
dev->name);
return 0;
}
ret = ipa_rm_inactivity_timer_request_resource(
ipa_rm_resource_by_ch_id[wwan_ptr->ch_id]);
if (ret == -EINPROGRESS) {
netif_stop_queue(dev);
return NETDEV_TX_BUSY;
}
if (ret) {
pr_err("[%s] fatal: ipa rm timer request resource failed %d\n",
dev->name, ret);
return -EFAULT;
}
ret = wwan_send_packet(skb, dev);
if (ret == -EPERM) {
ret = NETDEV_TX_BUSY;
goto exit;
}
/*
* detected SSR a bit early. shut some things down now, and leave
* the rest to the main ssr handling code when that happens later
*/
if (ret == -EFAULT) {
netif_carrier_off(dev);
dev_kfree_skb_any(skb);
ret = 0;
goto exit;
}
if (ret == -EAGAIN) {
/*
* This should not happen
* EAGAIN means we attempted to overflow the high watermark
* Clearly the queue is not stopped like it should be, so
* stop it and return BUSY to the TCP/IP framework. It will
* retry this packet with the queue is restarted which happens
* in the write_done callback when the low watermark is hit.
*/
netif_stop_queue(dev);
ret = NETDEV_TX_BUSY;
goto exit;
}
spin_lock_irqsave(&wwan_ptr->lock, flags);
if (a2_mux_is_ch_full(a2_mux_lcid_by_ch_id[wwan_ptr->ch_id])) {
netif_stop_queue(dev);
pr_debug("%s: High WM hit, stopping queue=%p\n",
__func__, skb);
}
spin_unlock_irqrestore(&wwan_ptr->lock, flags);
return ret;
exit:
ipa_rm_inactivity_timer_release_resource(
ipa_rm_resource_by_ch_id[wwan_ptr->ch_id]);
return ret;
}
