/*
* USB Network driver infrastructure
* Copyright (C) 2000-2005 by David Brownell
* Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* This is a generic "USB networking" framework that works with several
* kinds of full and high speed networking devices: host-to-host cables,
* smart usb peripherals, and actual Ethernet adapters.
*
* These devices usually differ in terms of control protocols (if they
* even have one!) and sometimes they define new framing to wrap or batch
* Ethernet packets. Otherwise, they talk to USB pretty much the same,
* so interface (un)binding, endpoint I/O queues, fault handling, and other
* issues can usefully be addressed by this framework.
*/
// #define DEBUG // error path messages, extra info
// #define VERBOSE // more; success messages
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include "usbnet.h"
#define DRIVER_VERSION "22-Aug-2005"
/*-------------------------------------------------------------------------*/
/*
* Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
* Several dozen bytes of IPv4 data can fit in two such transactions.
* One maximum size Ethernet packet takes twenty four of them.
* For high speed, each frame comfortably fits almost 36 max size
* Ethernet packets (so queues should be bigger).
*
* REVISIT qlens should be members of 'struct usbnet'; the goal is to
* let the USB host controller be busy for 5msec or more before an irq
* is required, under load. Jumbograms change the equation.
*/
#define RX_MAX_QUEUE_MEMORY (60 * 1518)
#define RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
(RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
#define TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
(RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
// reawaken network queue this soon after stopping; else watchdog barks
#define TX_TIMEOUT_JIFFIES (5*HZ)
// throttle rx/tx briefly after some faults, so khubd might disconnect()
// us (it polls at HZ/4 usually) before we report too many false errors.
#define THROTTLE_JIFFIES (HZ/8)
// between wakeups
#define UNLINK_TIMEOUT_MS 3
/*-------------------------------------------------------------------------*/
// randomly generated ethernet address
static u8 node_id [ETH_ALEN];
static const char driver_name [] = "usbnet";
/* use ethtool to change the level for any given device */
static int msg_level = -1;
module_param (msg_level, int, 0);
MODULE_PARM_DESC (msg_level, "Override default message level");
/*-------------------------------------------------------------------------*/
/* handles CDC Ethernet and many other network "bulk data" interfaces */
int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
{
int tmp;
struct usb_host_interface *alt = NULL;
struct usb_host_endpoint *in = NULL, *out = NULL;
struct usb_host_endpoint *status = NULL;
for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
unsigned ep;
in = out = status = NULL;
alt = intf->altsetting + tmp;
/* take the first altsetting with in-bulk + out-bulk;
* remember any status endpoint, just in case;
* ignore other endpoints and altsetttings.
*/
for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
struct usb_host_endpoint *e;
int intr = 0;
e = alt->endpoint + ep;
switch (e->desc.bmAttributes) {
case USB_ENDPOINT_XFER_INT:
if (!(e->desc.bEndpointAddress & USB_DIR_IN))
continue;
intr = 1;
/* FALLTHROUGH */
case USB_ENDPOINT_XFER_BULK:
break;
default:
continue;
}
if (e->desc.bEndpointAddress & USB_DIR_IN) {
if (!intr && !in)
in = e;
else if (intr && !status)
status = e;
} else {
if (!out)
out = e;
}
}
if (in && out)
break;
}
if (!alt || !in || !out)
return -EINVAL;
if (alt->desc.bAlternateSetting != 0
|| !(dev->driver_info->flags & FLAG_NO_SETINT)) {
tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
alt->desc.bAlternateSetting);
if (tmp < 0)
return tmp;
}
dev->in = usb_rcvbulkpipe (dev->udev,
in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
dev->out = usb_sndbulkpipe (dev->udev,
out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
dev->status = status;
return 0;
}
EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
static void intr_complete (struct urb *urb);
static int init_status (struct usbnet *dev, struct usb_interface *intf)
{
char *buf = NULL;
unsigned pipe = 0;
unsigned maxp;
unsigned period;
if (!dev->driver_info->status)
return 0;
pipe = usb_rcvintpipe (dev->udev,
dev->status->desc.bEndpointAddress
& USB_ENDPOINT_NUMBER_MASK);
maxp = usb_maxpacket (dev->udev, pipe, 0);
/* avoid 1 msec chatter: min 8 msec poll rate */
period = max ((int) dev->status->desc.bInterval,
(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
buf = kmalloc (maxp, SLAB_KERNEL);
if (buf) {
dev->interrupt = usb_alloc_urb (0, SLAB_KERNEL);
if (!dev->interrupt) {
kfree (buf);
return -ENOMEM;
} else {
usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
buf, maxp, intr_complete, dev, period);
dev_dbg(&intf->dev,
"status ep%din, %d bytes period %d\n",
usb_pipeendpoint(pipe), maxp, period);
}
}
return 0;
}
/* Passes this packet up the stack, updating its accounting.
* Some link protocols batch packets, so their rx_fixup paths
* can return clones as well as just modify the original skb.
*/
void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
{
int status;
skb->dev = dev->net;
skb->protocol = eth_type_trans (skb, dev->net);
dev->stats.rx_packets++;
dev->stats.rx_bytes += skb->len;
if (netif_msg_rx_status (dev))
devdbg (dev, "< rx, len %zu, type 0x%x",
skb->len + sizeof (struct ethhdr), skb->protocol);
memset (skb->cb, 0, sizeof (struct skb_data));
status = netif_rx (skb);
if (status != NET_RX_SUCCESS && netif_msg_rx_err (dev))
devdbg (dev, "netif_rx status %d", status);
}
EXPORT_SYMBOL_GPL(usbnet_skb_return);
/*-------------------------------------------------------------------------
*
* Network Device Driver (peer link to "Host Device", from USB host)
*
*-------------------------------------------------------------------------*/
static int usbnet_change_mtu (struct net_device *net, int new_mtu)
{
struct usbnet *dev = netdev_priv(net);
int ll_mtu = new_mtu + net->hard_header_len;
int old_hard_mtu = dev->hard_mtu;
int old_rx_urb_size = dev->rx_urb_size;
if (new_mtu <= 0)
return -EINVAL;
// no second zero-length packet read wanted after mtu-sized packets
if ((ll_mtu % dev->maxpacket) == 0)
return -EDOM;
net->mtu = new_mtu;
dev->hard_mtu = net->mtu + net->hard_header_len;
if (dev->rx_urb_size == old_hard_mtu) {
dev->rx_urb_size = dev->hard_mtu;
if (dev->rx_urb_size > old_rx_urb_size)
usbnet_unlink_rx_urbs(dev);
}
return 0;
}
/*-------------------------------------------------------------------------*/
static struct net_device_stats *usbnet_get_stats (struct net_device *net)
{
struct usbnet *dev = netdev_priv(net);
return &dev->stats;
}
/*-------------------------------------------------------------------------*/
/* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
* completion callbacks. 2.5 should have fixed those bugs...
*/
static void defer_bh(struct usbnet *dev, struct sk_buff *skb, struct sk_buff_head *list)
{
unsigned long flags;
spin_lock_irqsave(&list->lock, flags);
__skb_unlink(skb, list);
spin_unlock(&list->lock);
spin_lock(&dev->done.lock);
__skb_queue_tail(&dev->done, skb);
if (dev->done.qlen == 1)
tasklet_schedule(&dev->bh);
spin_unlock_irqrestore(&dev->done.lock, flags);
}
/* some work can't be done in tasklets, so we use keventd
*
* NOTE: annoying asymmetry: if it's active, schedule_work() fails,
* but tasklet_schedule() doesn't. hope the failure is rare.
*/
void usbnet_defer_kevent (struct usbnet *dev, int work)
{
set_bit (work, &dev->flags);
if (!schedule_work (&dev->kevent))
deverr (dev, "kevent %d may have been dropped", work);
else
devdbg (dev, "kevent %d scheduled", work);
}
EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
/*-------------------------------------------------------------------------*/
static void rx_complete (struct urb *urb);
static void rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
{
struct sk_buff *skb;
struct skb_data *entry;
int retval = 0;
unsigned long lockflags;
size_t size = dev->rx_urb_size;
if ((skb = alloc_skb (size + NET_IP_ALIGN, flags)) == NULL) {
if (netif_msg_rx_err (dev))
devdbg (dev, "no rx skb");
usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
usb_free_urb (urb);
return;
}
skb_reserve (skb, NET_IP_ALIGN);
entry = (struct skb_data *) skb->cb;
entry->urb = urb;
entry->dev = dev;
entry->state = rx_start;
entry->length = 0;
usb_fill_bulk_urb (urb, dev->udev, dev->in,
skb->data, size, rx_complete, skb);
spin_lock_irqsave (&dev->rxq.lock, lockflags);
if (netif_running (dev->net)
&& netif_device_present (dev->net)
&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
switch (retval = usb_submit_urb (urb, GFP_ATOMIC)){
case -EPIPE:
usbnet_defer_kevent (dev, EVENT_RX_HALT);
break;
case -ENOMEM:
usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
break;
case -ENODEV:
if (netif_msg_ifdown (dev))
devdbg (dev, "device gone");
netif_device_detach (dev->net);
break;
default:
if (netif_msg_rx_err (dev))
devdbg (dev, "rx submit, %d", retval);
tasklet_schedule (&dev->bh);
break;
case 0:
__skb_queue_tail (&dev->rxq, skb);
}
} else {
if (netif_msg_ifdown (dev))
devdbg (dev, "rx: stopped");
retval = -ENOLINK;
}
spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
if (retval) {
dev_kfree_skb_any (skb);
usb_free_urb (urb);
}
}
/*-------------------------------------------------------------------------*/
static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
{
if (dev->driver_info->rx_fixup
&& !dev->driver_info->rx_fixup (dev, skb))
goto error;
// else network stack removes extra byte if we forced a short packet
if (skb->len)
usbnet_skb_return (dev, skb);
else {
if (netif_msg_rx_err (dev))
devdbg (dev, "drop");
error:
dev->stats.rx_errors++;
skb_queue_tail (&dev->done, skb);
}
}
/*-------------------------------------------------------------------------*/
static void rx_complete (struct urb *urb)
{
struct sk_buff *skb = (struct sk_buff *) urb->context;
struct skb_data *entry = (struct skb_data *) skb->cb;
struct usbnet *dev = entry->dev;
int urb_status = urb->status;
skb_put (skb, urb->actual_length);
entry->state = rx_done;
entry->urb = NULL;
switch (urb_status) {
// success
case 0:
if (skb->len < dev->net->hard_header_len) {
entry->state = rx_cleanup;
dev->stats.rx_errors++;
dev->stats.rx_length_errors++;
if (netif_msg_rx_err (dev))
devdbg (dev, "rx length %d", skb->len);
}
break;
// stalls need manual reset. this is rare ... except that
// when going through USB 2.0 TTs, unplug appears this way.
// we avoid the highspeed version of the ETIMEOUT/EILSEQ
// storm, recovering as needed.
case -EPIPE:
dev->stats.rx_errors++;
usbnet_defer_kevent (dev, EVENT_RX_HALT);
// FALLTHROUGH
// software-driven interface shutdown
case -ECONNRESET: // async unlink
case -ESHUTDOWN: // hardware gone
if (netif_msg_ifdown (dev))
devdbg (dev, "rx shutdown, code %d", urb_status);
goto block;
// we get controller i/o faults during khubd disconnect() delays.
// throttle down resubmits, to avoid log floods; just temporarily,
// so we still recover when the fault isn't a khubd delay.
case -EPROTO:
case -ETIME:
case -EILSEQ:
dev->stats.rx_errors++;
if (!timer_pending (&dev->delay)) {
mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
if (netif_msg_link (dev))
devdbg (dev, "rx throttle %d", urb_status);
}
block:
entry->state = rx_cleanup;
entry->urb = urb;
urb = NULL;
break;
// data overrun ... flush fifo?
case -EOVERFLOW:
dev->stats.rx_over_errors++;
// FALLTHROUGH
default:
entry->state = rx_cleanup;
dev->stats.rx_errors++;
if (netif_msg_rx_err (dev))
devdbg (dev, "rx status %d", urb_status);
break;
}
defer_bh(dev, skb, &dev->rxq);
if (urb) {
if (netif_running (dev->net)
&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
rx_submit (dev, urb, GFP_ATOMIC);
return;
}
usb_free_urb (urb);
}
if (netif_msg_rx_err (dev))
devdbg (dev, "no read resubmitted");
}
static void intr_complete (struct urb *urb)
{
struct usbnet *dev = urb->context;
int status = urb->status;
switch (status) {
/* success */
case 0:
dev->driver_info->status(dev, urb);
break;
/* software-driven interface shutdown */
case -ENOENT: // urb killed
case -ESHUTDOWN: // hardware gone
if (netif_msg_ifdown (dev))
devdbg (dev, "intr shutdown, code %d", status);
return;
/* NOTE: not throttling like RX/TX, since this endpoint
* already polls infrequently
*/
default:
devdbg (dev, "intr status %d", status);
break;
}
if (!netif_running (dev->net))
return;
memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
status = usb_submit_urb (urb, GFP_ATOMIC);
if (status != 0 && netif_msg_timer (dev))
deverr(dev, "intr resubmit --> %d", status);
}
/*-------------------------------------------------------------------------*/
// unlink pending rx/tx; completion handlers do all other cleanup
static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
{
unsigned long flags;
struct sk_buff *skb, *skbnext;
int count = 0;
spin_lock_irqsave (&q->lock, flags);
for (skb = q->next; skb != (struct sk_buff *) q; skb = skbnext) {
struct skb_data *entry;
struct urb *urb;
int retval;
entry = (struct skb_data *) skb->cb;
urb = entry->urb;
skbnext = skb->next;
// during some PM-driven resume scenarios,
// these (async) unlinks complete immediately
retval = usb_unlink_urb (urb);
if (retval != -EINPROGRESS && retval != 0)
devdbg (dev, "unlink urb err, %d", retval);
else
count++;
}
spin_unlock_irqrestore (&q->lock, flags);
return count;
}
// Flush all pending rx urbs
// minidrivers may need to do this when the MTU changes
void usbnet_unlink_rx_urbs(struct usbnet *dev)
{
if (netif_running(dev->net)) {
(void) unlink_urbs (dev, &dev->rxq);
tasklet_schedule(&dev->bh);
}
}
EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
/*-------------------------------------------------------------------------*/
// precondition: never called in_interrupt
static int usbnet_stop (struct net_device *net)
{
struct usbnet *dev = netdev_priv(net);
int temp;
DECLARE_WAIT_QUEUE_HEAD_ONSTACK (unlink_wakeup);
DECLARE_WAITQUEUE (wait, current);
netif_stop_queue (net);
if (netif_msg_ifdown (dev))
devinfo (dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld",
dev->stats.rx_packets, dev->stats.tx_packets,
dev->stats.rx_errors, dev->stats.tx_errors
);
// ensure there are no more active urbs
add_wait_queue (&unlink_wakeup, &wait);
dev->wait = &unlink_wakeup;
temp = unlink_urbs (dev, &dev->txq) + unlink_urbs (dev, &dev->rxq);
// maybe wait for deletions to finish.
while (!skb_queue_empty(&dev->rxq) &&
!skb_queue_empty(&dev->txq) &&
!skb_queue_empty(&dev->done)) {
msleep(UNLINK_TIMEOUT_MS);
if (netif_msg_ifdown (dev))
devdbg (dev, "waited for %d urb completions", temp);
}
dev->wait = NULL;
remove_wait_queue (&unlink_wakeup, &wait);
usb_kill_urb(dev->interrupt);
/* deferred work (task, timer, softirq) must also stop.
* can't flush_scheduled_work() until we drop rtnl (later),
* else workers could deadlock; so make workers a NOP.
*/
dev->flags = 0;
del_timer_sync (&dev->delay);
tasklet_kill (&dev->bh);
return 0;
}
/*-------------------------------------------------------------------------*/
// posts reads, and enables write queuing
// precondition: never called in_interrupt
static int usbnet_open (struct net_device *net)
{
struct usbnet *dev = netdev_priv(net);
int retval = 0;
struct driver_info *info = dev->driver_info;
// put into "known safe" state
if (info->reset && (retval = info->reset (dev)) < 0) {
if (netif_msg_ifup (dev))
devinfo (dev,
"open reset fail (%d) usbnet usb-%s-%s, %s",
retval,
dev->udev->bus->bus_name, dev->udev->devpath,
info->description);
goto done;
}
// insist peer be connected
if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
if (netif_msg_ifup (dev))
devdbg (dev, "can't open; %d", retval);
goto done;
}
/* start any status interrupt transfer */
if (dev->interrupt) {
retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
if (retval < 0) {
if (netif_msg_ifup (dev))
deverr (dev, "intr submit %d", retval);
goto done;
}
}
netif_start_queue (net);
if (netif_msg_ifup (dev)) {
char *framing;
if (dev->driver_info->flags & FLAG_FRAMING_NC)
framing = "NetChip";
else if (dev->driver_info->flags & FLAG_FRAMING_GL)
framing = "GeneSys";
else if (dev->driver_info->flags & FLAG_FRAMING_Z)
framing = "Zaurus";
else if (dev->driver_info->flags & FLAG_FRAMING_RN)
framing = "RNDIS";
else if (dev->driver_info->flags & FLAG_FRAMING_AX)
framing = "ASIX";
else
framing = "simple";
devinfo (dev, "open: enable queueing "
"(rx %d, tx %d) mtu %d %s framing",
(int)RX_QLEN (dev), (int)TX_QLEN (dev), dev->net->mtu,
framing);
}
// delay posting reads until we're fully open
tasklet_schedule (&dev->bh);
done:
return retval;
}
/*-------------------------------------------------------------------------*/
/* ethtool methods; minidrivers may need to add some more, but
* they'll probably want to use this base set.
*/
#if defined(CONFIG_MII) || defined(CONFIG_MII_MODULE)
#define HAVE_MII
int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
{
struct usbnet *dev = netdev_priv(net);
if (!dev->mii.mdio_read)
return -EOPNOTSUPP;
return mii_ethtool_gset(&dev->mii, cmd);
}
EXPORT_SYMBOL_GPL(usbnet_get_settings);
int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
{
struct usbnet *dev = netdev_priv(net);
int retval;
if (!dev->mii.mdio_write)
return -EOPNOTSUPP;
retval = mii_ethtool_sset(&dev->mii, cmd);
/* link speed/duplex might have changed */
if (dev->driver_info->link_reset)
dev->driver_info->link_reset(dev);
return retval;
}
EXPORT_SYMBOL_GPL(usbnet_set_settings);
u32 usbnet_get_link (struct net_device *net)
{
struct usbnet *dev = netdev_priv(net);
/* If a check_connect is defined, return its result */
if (dev->driver_info->check_connect)
return dev->driver_info->check_connect (dev) == 0;
/* if the device has mii operations, use those */
if (dev->mii.mdio_read)
return mii_link_ok(&dev->mii);
/* Otherwise, say we're up (to avoid breaking scripts) */
return 1;
}
EXPORT_SYMBOL_GPL(usbnet_get_link);
int usbnet_nway_reset(struct net_device *net)
{
struct usbnet *dev = netdev_priv(net);
if (!dev->mii.mdio_write)
return -EOPNOTSUPP;
return mii_nway_restart(&dev->mii);
}
EXPORT_SYMBOL_GPL(usbnet_nway_reset);
#endif /* HAVE_MII */
void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
{
struct usbnet *dev = netdev_priv(net);
/* REVISIT don't always return "usbnet" */
strncpy (info->driver, driver_name, sizeof info->driver);
strncpy (info->version, DRIVER_VERSION, sizeof info->version);
strncpy (info->fw_version, dev->driver_info->description,
sizeof info->fw_version);
usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
}
EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
u32 usbnet_get_msglevel (struct net_device *net)
{
struct usbnet *dev = netdev_priv(net);
return dev->msg_enable;
}
EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
void usbnet_set_msglevel (struct net_device *net, u32 level)
{
struct usbnet *dev = netdev_priv(net);
dev->msg_enable = level;
}
EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
/* drivers may override default ethtool_ops in their bind() routine */
static struct ethtool_ops usbnet_ethtool_ops = {
#ifdef HAVE_MII
.get_settings = usbnet_get_settings,
.set_settings = usbnet_set_settings,
.get_link = usbnet_get_link,
.nway_reset = usbnet_nway_reset,
#endif
.get_drvinfo = usbnet_get_drvinfo,
.get_msglevel = usbnet_get_msglevel,
.set_msglevel = usbnet_set_msglevel,
};
/*-------------------------------------------------------------------------*/
/* work that cannot be done in interrupt context uses keventd.
*
* NOTE: with 2.5 we could do more of this using completion callbacks,
* especially now that control transfers can be queued.
*/
static void
kevent (void *data)
{
struct usbnet *dev = data;
int status;
/* usb_clear_halt() needs a thread context */
if (test_bit (EVENT_TX_HALT, &dev->flags)) {
unlink_urbs (dev, &dev->txq);
status = usb_clear_halt (dev->udev, dev->out);
if (status < 0
&& status != -EPIPE
&& status != -ESHUTDOWN) {
if (netif_msg_tx_err (dev))
deverr (dev, "can't clear tx halt, status %d",
status);
} else {
clear_bit (EVENT_TX_HALT, &dev->flags);
if (status != -ESHUTDOWN)
netif_wake_queue (dev->net);
}
}
if (test_bit (EVENT_RX_HALT, &dev->flags)) {
unlink_urbs (dev, &dev->rxq);
status = usb_clear_halt (dev->udev, dev->in);
if (status < 0
&& status != -EPIPE
&& status != -ESHUTDOWN) {
if (netif_msg_rx_err (dev))
deverr (dev, "can't clear rx halt, status %d",
status);
} else {
clear_bit (EVENT_RX_HALT, &dev->flags);
tasklet_schedule (&dev->bh);
}
}
/* tasklet could resubmit itself forever if memory is tight */
if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
struct urb *urb = NULL;
if (netif_running (dev->net))
urb = usb_alloc_urb (0, GFP_KERNEL);
else
clear_bit (EVENT_RX_MEMORY, &dev->flags);
if (urb != NULL) {
clear_bit (EVENT_RX_MEMORY, &dev->flags);
rx_submit (dev, urb, GFP_KERNEL);
tasklet_schedule (&dev->bh);
}
}
if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
struct driver_info *info = dev->driver_info;
int retval = 0;
clear_bit (EVENT_LINK_RESET, &dev->flags);
if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
devinfo(dev, "link reset failed (%d) usbnet usb-%s-%s, %s",
retval,
dev->udev->bus->bus_name, dev->udev->devpath,
info->description);
}
}
if (dev->flags)
devdbg (dev, "kevent done, flags = 0x%lx",
dev->flags);
}
/*-------------------------------------------------------------------------*/
static void tx_complete (struct urb *urb)
{
struct sk_buff *skb = (struct sk_buff *) urb->context;
struct skb_data *entry = (struct skb_data *) skb->cb;
struct usbnet *dev = entry->dev;
if (urb->status == 0) {
dev->stats.tx_packets++;
dev->stats.tx_bytes += entry->length;
} else {
dev->stats.tx_errors++;
switch (urb->status) {
case -EPIPE:
usbnet_defer_kevent (dev, EVENT_TX_HALT);
break;
/* software-driven interface shutdown */
case -ECONNRESET: // async unlink
case -ESHUTDOWN: // hardware gone
break;
// like rx, tx gets controller i/o faults during khubd delays
// and so it uses the same throttling mechanism.
case -EPROTO:
case -ETIME:
case -EILSEQ:
if (!timer_pending (&dev->delay)) {
mod_timer (&dev->delay,
jiffies + THROTTLE_JIFFIES);
if (netif_msg_link (dev))
devdbg (dev, "tx throttle %d",
urb->status);
}
netif_stop_queue (dev->net);
break;
default:
if (netif_msg_tx_err (dev))
devdbg (dev, "tx err %d", entry->urb->status);
break;
}
}
urb->dev = NULL;
entry->state = tx_done;
defer_bh(dev, skb, &dev->txq);
}
/*-------------------------------------------------------------------------*/
static void usbnet_tx_timeout (struct net_device *net)
{
struct usbnet *dev = netdev_priv(net);
unlink_urbs (dev, &dev->txq);
tasklet_schedule (&dev->bh);
// FIXME: device recovery -- reset?
}
/*-------------------------------------------------------------------------*/
static int usbnet_start_xmit (struct sk_buff *skb, struct net_device *net)
{
struct usbnet *dev = netdev_priv(net);
int length;
int retval = NET_XMIT_SUCCESS;
struct urb *urb = NULL;
struct skb_data *entry;
struct driver_info *info = dev->driver_info;
unsigned long flags;
// some devices want funky USB-level framing, for
// win32 driver (usually) and/or hardware quirks
if (info->tx_fixup) {
skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
if (!skb) {
if (netif_msg_tx_err (dev))
devdbg (dev, "can't tx_fixup skb");
goto drop;
}
}
length = skb->len;
if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
if (netif_msg_tx_err (dev))
devdbg (dev, "no urb");
goto drop;
}
entry = (struct skb_data *) skb->cb;
entry->urb = urb;
entry->dev = dev;
entry->state = tx_start;
entry->length = length;
usb_fill_bulk_urb (urb, dev->udev, dev->out,
skb->data, skb->len, tx_complete, skb);
/* don't assume the hardware handles USB_ZERO_PACKET
* NOTE: strictly conforming cdc-ether devices should expect
* the ZLP here, but ignore the one-byte packet.
*
* FIXME zero that byte, if it doesn't require a new skb.
*/
if ((length % dev->maxpacket) == 0)
urb->transfer_buffer_length++;
spin_lock_irqsave (&dev->txq.lock, flags);
switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
case -EPIPE:
netif_stop_queue (net);
usbnet_defer_kevent (dev, EVENT_TX_HALT);
break;
default:
if (netif_msg_tx_err (dev))
devdbg (dev, "tx: submit urb err %d", retval);
break;
case 0:
net->trans_start = jiffies;
__skb_queue_tail (&dev->txq, skb);
if (dev->txq.qlen >= TX_QLEN (dev))
netif_stop_queue (net);
}
spin_unlock_irqrestore (&dev->txq.lock, flags);
if (retval) {
if (netif_msg_tx_err (dev))
devdbg (dev, "drop, code %d", retval);
drop:
retval = NET_XMIT_SUCCESS;
dev->stats.tx_dropped++;
if (skb)
dev_kfree_skb_any (skb);
usb_free_urb (urb);
} else if (netif_msg_tx_queued (dev)) {
devdbg (dev, "> tx, len %d, type 0x%x",
length, skb->protocol);
}
return retval;
}
/*-------------------------------------------------------------------------*/
// tasklet (work deferred from completions, in_irq) or timer
static void usbnet_bh (unsigned long param)
{
struct usbnet *dev = (struct usbnet *) param;
struct sk_buff *skb;
struct skb_data *entry;
while ((skb = skb_dequeue (&dev->done))) {
entry = (struct skb_data *) skb->cb;
switch (entry->state) {
case rx_done:
entry->state = rx_cleanup;
rx_process (dev, skb);
continue;
case tx_done:
case rx_cleanup:
usb_free_urb (entry->urb);
dev_kfree_skb (skb);
continue;
default:
devdbg (dev, "bogus skb state %d", entry->state);
}
}
// waiting for all pending urbs to complete?
if (dev->wait) {
if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
wake_up (dev->wait);
}
// or are we maybe short a few urbs?
} else if (netif_running (dev->net)
&& netif_device_present (dev->net)
&& !timer_pending (&dev->delay)
&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
int temp = dev->rxq.qlen;
int qlen = RX_QLEN (dev);
if (temp < qlen) {
struct urb *urb;
int i;
// don't refill the queue all at once
for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
urb = usb_alloc_urb (0, GFP_ATOMIC);
if (urb != NULL)
rx_submit (dev, urb, GFP_ATOMIC);
}
if (temp != dev->rxq.qlen && netif_msg_link (dev))
devdbg (dev, "rxqlen %d --> %d",
temp, dev->rxq.qlen);
if (dev->rxq.qlen < qlen)
tasklet_schedule (&dev->bh);
}
if (dev->txq.qlen < TX_QLEN (dev))
netif_wake_queue (dev->net);
}
}
/*-------------------------------------------------------------------------
*
* USB Device Driver support
*
*-------------------------------------------------------------------------*/
// precondition: never called in_interrupt
void usbnet_disconnect (struct usb_interface *intf)
{
struct usbnet *dev;
struct usb_device *xdev;
struct net_device *net;
dev = usb_get_intfdata(intf);
usb_set_intfdata(intf, NULL);
if (!dev)
return;
xdev = interface_to_usbdev (intf);
if (netif_msg_probe (dev))
devinfo (dev, "unregister '%s' usb-%s-%s, %s",
intf->dev.driver->name,
xdev->bus->bus_name, xdev->devpath,
dev->driver_info->description);
net = dev->net;
unregister_netdev (net);
/* we don't hold rtnl here ... */
flush_scheduled_work ();
if (dev->driver_info->unbind)
dev->driver_info->unbind (dev, intf);
free_netdev(net);
usb_put_dev (xdev);
}
EXPORT_SYMBOL_GPL(usbnet_disconnect);
/*-------------------------------------------------------------------------*/
// precondition: never called in_interrupt
int
usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
{
struct usbnet *dev;
struct net_device *net;
struct usb_host_interface *interface;
struct driver_info *info;
struct usb_device *xdev;
int status;
info = (struct driver_info *) prod->driver_info;
if (!info) {
dev_dbg (&udev->dev, "blacklisted by %s\n", driver_name);
return -ENODEV;
}
xdev = interface_to_usbdev (udev);
interface = udev->cur_altsetting;
usb_get_dev (xdev);
status = -ENOMEM;
// set up our own records
net = alloc_etherdev(sizeof(*dev));
if (!net) {
dbg ("can't kmalloc dev");
goto out;
}
dev = netdev_priv(net);
dev->udev = xdev;
dev->driver_info = info;
dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
| NETIF_MSG_PROBE | NETIF_MSG_LINK);
skb_queue_head_init (&dev->rxq);
skb_queue_head_init (&dev->txq);
skb_queue_head_init (&dev->done);
dev->bh.func = usbnet_bh;
dev->bh.data = (unsigned long) dev;
INIT_WORK (&dev->kevent, kevent, dev);
dev->delay.function = usbnet_bh;
dev->delay.data = (unsigned long) dev;
init_timer (&dev->delay);
mutex_init (&dev->phy_mutex);
SET_MODULE_OWNER (net);
dev->net = net;
strcpy (net->name, "usb%d");
memcpy (net->dev_addr, node_id, sizeof node_id);
/* rx and tx sides can use different message sizes;
* bind() should set rx_urb_size in that case.
*/
dev->hard_mtu = net->mtu + net->hard_header_len;
#if 0
// dma_supported() is deeply broken on almost all architectures
// possible with some EHCI controllers
if (dma_supported (&udev->dev, DMA_64BIT_MASK))
net->features |= NETIF_F_HIGHDMA;
#endif
net->change_mtu = usbnet_change_mtu;
net->get_stats = usbnet_get_stats;
net->hard_start_xmit = usbnet_start_xmit;
net->open = usbnet_open;
net->stop = usbnet_stop;
net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
net->tx_timeout = usbnet_tx_timeout;
net->ethtool_ops = &usbnet_ethtool_ops;
// allow device-specific bind/init procedures
// NOTE net->name still not usable ...
if (info->bind) {
status = info->bind (dev, udev);
// heuristic: "usb%d" for links we know are two-host,
// else "eth%d" when there's reasonable doubt. userspace
// can rename the link if it knows better.
if ((dev->driver_info->flags & FLAG_ETHER) != 0
&& (net->dev_addr [0] & 0x02) == 0)
strcpy (net->name, "eth%d");
/* maybe the remote can't receive an Ethernet MTU */
if (net->mtu > (dev->hard_mtu - net->hard_header_len))
net->mtu = dev->hard_mtu - net->hard_header_len;
} else if (!info->in || !info->out)
status = usbnet_get_endpoints (dev, udev);
else {
dev->in = usb_rcvbulkpipe (xdev, info->in);
dev->out = usb_sndbulkpipe (xdev, info->out);
if (!(info->flags & FLAG_NO_SETINT))
status = usb_set_interface (xdev,
interface->desc.bInterfaceNumber,
interface->desc.bAlternateSetting);
else
status = 0;
}
if (status == 0 && dev->status)
status = init_status (dev, udev);
if (status < 0)
goto out1;
if (!dev->rx_urb_size)
dev->rx_urb_size = dev->hard_mtu;
dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
SET_NETDEV_DEV(net, &udev->dev);
status = register_netdev (net);
if (status)
goto out3;
if (netif_msg_probe (dev))
devinfo (dev, "register '%s' at usb-%s-%s, %s, "
"%02x:%02x:%02x:%02x:%02x:%02x",
udev->dev.driver->name,
xdev->bus->bus_name, xdev->devpath,
dev->driver_info->description,
net->dev_addr [0], net->dev_addr [1],
net->dev_addr [2], net->dev_addr [3],
net->dev_addr [4], net->dev_addr [5]);
// ok, it's ready to go.
usb_set_intfdata (udev, dev);
// start as if the link is up
netif_device_attach (net);
return 0;
out3:
if (info->unbind)
info->unbind (dev, udev);
out1:
free_netdev(net);
out:
usb_put_dev(xdev);
return status;
}
EXPORT_SYMBOL_GPL(usbnet_probe);
/*-------------------------------------------------------------------------*/
/* FIXME these suspend/resume methods assume non-CDC style
* devices, with only one interface.
*/
int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
{
struct usbnet *dev = usb_get_intfdata(intf);
/* accelerate emptying of the rx and queues, to avoid
* having everything error out.
*/
netif_device_detach (dev->net);
(void) unlink_urbs (dev, &dev->rxq);
(void) unlink_urbs (dev, &dev->txq);
return 0;
}
EXPORT_SYMBOL_GPL(usbnet_suspend);
int usbnet_resume (struct usb_interface *intf)
{
struct usbnet *dev = usb_get_intfdata(intf);
netif_device_attach (dev->net);
tasklet_schedule (&dev->bh);
return 0;
}
EXPORT_SYMBOL_GPL(usbnet_resume);
/*-------------------------------------------------------------------------*/
static int __init usbnet_init(void)
{
/* compiler should optimize this out */
BUILD_BUG_ON (sizeof (((struct sk_buff *)0)->cb)
< sizeof (struct skb_data));
random_ether_addr(node_id);
return 0;
}
module_init(usbnet_init);
static void __exit usbnet_exit(void)
{
}
module_exit(usbnet_exit);
MODULE_AUTHOR("David Brownell");
MODULE_DESCRIPTION("USB network driver framework");
MODULE_LICENSE("GPL");
