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;
}
static int __wwan_close(struct net_device *dev)
{
struct wwan_private *wwan_ptr = netdev_priv(dev);
int rc = 0;
if (wwan_ptr->device_status == WWAN_DEVICE_ACTIVE) {
wwan_ptr->device_status = WWAN_DEVICE_INACTIVE;
/* do not close wwan port once up, this causes
remote side to hang if tried to open again */
INIT_COMPLETION(wwan_ptr->resource_granted_completion);
rc = ipa_rm_inactivity_timer_request_resource(
ipa_rm_resource_by_ch_id[wwan_ptr->ch_id]);
if (rc < 0 && rc != -EINPROGRESS) {
pr_err("%s: ipa rm timer request resource failed %d\n",
__func__, rc);
return -ENODEV;
}
if (rc == -EINPROGRESS) {
wait_for_completion(
&wwan_ptr->resource_granted_completion);
}
rc = a2_mux_close_channel(
a2_mux_lcid_by_ch_id[wwan_ptr->ch_id]);
if (rc) {
pr_err("[%s] %s: a2_mux_close_channel failed %d\n",
dev->name, __func__, rc);
ipa_rm_inactivity_timer_release_resource(
ipa_rm_resource_by_ch_id[wwan_ptr->ch_id]);
return rc;
}
ipa_rm_inactivity_timer_release_resource(
ipa_rm_resource_by_ch_id[wwan_ptr->ch_id]);
rc = ipa_deregister_intf(dev->name);
if (rc) {
pr_err("[%s] %s: ipa_deregister_intf failed %d\n",
dev->name, __func__, rc);
return rc;
}
return rc;
} else
return -EBADF;
}
static int __wwan_open(struct net_device *dev)
{
int r;
struct wwan_private *wwan_ptr = netdev_priv(dev);
pr_debug("[%s] __wwan_open()\n", dev->name);
if (wwan_ptr->device_status != WWAN_DEVICE_ACTIVE) {
INIT_COMPLETION(wwan_ptr->resource_granted_completion);
r = ipa_rm_inactivity_timer_request_resource(
ipa_rm_resource_by_ch_id[wwan_ptr->ch_id]);
if (r < 0 && r != -EINPROGRESS) {
pr_err("%s: ipa rm timer request resource failed %d\n",
__func__, r);
return -ENODEV;
}
if (r == -EINPROGRESS) {
wait_for_completion(
&wwan_ptr->resource_granted_completion);
}
r = a2_mux_open_channel(a2_mux_lcid_by_ch_id[wwan_ptr->ch_id],
dev, a2_mux_notify);
if (r < 0) {
pr_err("%s: ch=%d failed with rc %d\n",
__func__, wwan_ptr->ch_id, r);
ipa_rm_inactivity_timer_release_resource(
ipa_rm_resource_by_ch_id[wwan_ptr->ch_id]);
return -ENODEV;
}
ipa_rm_inactivity_timer_release_resource(
ipa_rm_resource_by_ch_id[wwan_ptr->ch_id]);
r = wwan_register_to_ipa(dev);
if (r < 0) {
pr_err("%s: ch=%d failed to register to IPA rc %d\n",
__func__, wwan_ptr->ch_id, r);
return -ENODEV;
}
}
wwan_ptr->device_status = WWAN_DEVICE_ACTIVE;
return 0;
}
/**
* 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;
}
