解决“ipheth_tx_timeout: TX timeout”

在调试iOS的usb tethering时发现这个问题的。（如何搭建iOS的usb tethering请看我的这篇文章《OpenWrt支持usb tethering》）

其实当前主流Linux（如Ubuntu）使用的Diego Giagio作者的ipheth，功能性是好的，但稳定性不足。
废话少说

code：

<基于kernel 3.3.8>
linux-3.3.8/drivers/net/usb/ipheth.c

/* * Copyright (C) 2017 Walker Wei<[e-mail]>. All rights reserved. * Copyright (C) 2009 Diego Giagio. All rights reserved. * Copyright (C) 2000-2005 by David Brownell * Copyright (C) 2003-2005 David Hollis <[e-mail]> * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright *    notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright *    notice, this list of conditions and the following disclaimer in the *    documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. *//* * Thanks to Diego Giagio for figuring out the programming details for * the Apple iPhone Ethernet driver. * This program is based on usbnet which is written by David Brownell. */#include <linux/module.h>#include <linux/init.h>#include <linux/netdevice.h>#include <linux/etherdevice.h>#include <linux/ethtool.h>#include <linux/workqueue.h>#include <linux/slab.h>#include <linux/mii.h>#include <linux/usb.h>#include <linux/usb/cdc.h>#include <linux/usb/usbnet.h>#define USB_VENDOR_APPLE        0x05ac#define USB_PRODUCT_IPHONE      0x1290#define USB_PRODUCT_IPHONE_3G   0x1292#define USB_PRODUCT_IPHONE_3GS  0x1294#define USB_PRODUCT_IPHONE_4    0x1297#define USB_PRODUCT_IPHONE_4_VZW 0x129c#define USB_PRODUCT_IPHONE_4S   0x12a0#define USB_PRODUCT_IPHONE_5   0x12a8#define USB_PRODUCT_IPAD       0x129a#define USB_PRODUCT_IPAD_MINI  0x12ab#define IPHETH_USBINTF_CLASS    255#define IPHETH_USBINTF_SUBCLASS 253#define IPHETH_USBINTF_PROTO    1#define IPHETH_INTFNUM          2#define IPHETH_ALT_INTFNUM      1#define IPHETH_BUF_SIZE         1516#define IPHETH_IP_ALIGN         2      /* padding at front of URB */#define IPHETH_CTRL_ENDP        0x00#define IPHETH_CTRL_BUF_SIZE    0x40#define IPHETH_CTRL_TIMEOUT     (5 * HZ)#define IPHETH_CMD_GET_MACADDR   0x00#define IPHETH_CMD_CARRIER_CHECK 0x45#define IPHETH_CARRIER_CHECK_TIMEOUT round_jiffies_relative(1 * HZ)#define IPHETH_CARRIER_ON       0x04static struct ipheth_local local;struct ipheth_local {    struct usbnet *dev;    struct mutex local_mutex;    struct delayed_work carrier_work;};/* same as usbnet_netdev_ops but MTU change not allowed */static const struct net_device_ops ipheth_netdev_ops = {    .ndo_open       = usbnet_open,    .ndo_stop       = usbnet_stop,    .ndo_start_xmit     = usbnet_start_xmit,    .ndo_tx_timeout     = usbnet_tx_timeout,    .ndo_set_mac_address    = eth_mac_addr,    .ndo_validate_addr  = eth_validate_addr,};void ipheth_status(struct usbnet *dev, struct urb *urb){    netdev_dbg(dev->net, "ipheth status urb, len %d stat %d\n",            urb->actual_length, urb->status);}EXPORT_SYMBOL_GPL(ipheth_status);static int ipheth_carrier_set(struct usbnet *dev){    struct usb_device *udev = NULL;    int retval = 0;    unsigned char ctrl_buf[IPHETH_CTRL_BUF_SIZE] = {0};    if (NULL == dev)    {        err("%s: struct usbnet *dev is NULL.", __func__);        retval = -EINVAL;        return retval;    }    udev = dev->udev;    retval = usb_control_msg(udev,            usb_rcvctrlpipe(udev, IPHETH_CTRL_ENDP),            IPHETH_CMD_CARRIER_CHECK, /* request */            0xc0, /* request type */            0x00, /* value */            0x02, /* index */            (void *)ctrl_buf,            IPHETH_CTRL_BUF_SIZE,            IPHETH_CTRL_TIMEOUT);    if (retval < 0) {        err("%s: usb_control_msg: %d", __func__, retval);    }    else    {        if (ctrl_buf[0] == IPHETH_CARRIER_ON)            netif_carrier_on(dev->net);        else            netif_carrier_off(dev->net);    }    return retval;}static void ipheth_carrier_check_work(struct work_struct *work){    struct usbnet *dev = NULL;    mutex_lock(&(local.local_mutex));    dev = local.dev;    ipheth_carrier_set(dev);    schedule_delayed_work(&(local.carrier_work), IPHETH_CARRIER_CHECK_TIMEOUT);    mutex_unlock(&(local.local_mutex));}static int ipheth_get_macaddr(struct usbnet *dev){    struct usb_device *udev = dev->udev;    struct net_device *net = dev->net;    int retval;    unsigned char ctrl_buf[IPHETH_CTRL_BUF_SIZE] = {0};    retval = usb_control_msg(udev,                 usb_rcvctrlpipe(udev, IPHETH_CTRL_ENDP),                 IPHETH_CMD_GET_MACADDR, /* request */                 0xc0, /* request type */                 0x00, /* value */                 0x02, /* index */                 (void *)ctrl_buf,                 IPHETH_CTRL_BUF_SIZE,                 IPHETH_CTRL_TIMEOUT);    if (retval < 0) {        err("%s: usb_control_msg: %d", __func__, retval);    } else if (retval < ETH_ALEN) {        err("%s: usb_control_msg: short packet: %d bytes",            __func__, retval);        retval = -EINVAL;    } else {        memcpy(net->dev_addr, (const void *)ctrl_buf, ETH_ALEN);        memcpy(net->perm_addr, (const void *)ctrl_buf, ETH_ALEN);        retval = 0;    }    return retval;}static int ipheth_bind(struct usbnet *dev, struct usb_interface *intf){    int retval = 0;//success    int i = 0;    struct usb_host_interface *hintf;    struct usb_endpoint_descriptor *endp;    u8 bulk_in = 0;    u8 bulk_out = 0;    /* Set up endpoints */    hintf = usb_altnum_to_altsetting(intf, IPHETH_ALT_INTFNUM);    if (hintf == NULL) {        retval = -ENODEV;        err("Unable to find alternate settings interface, retval=%d", retval);        return retval;    }    for (i = 0; i < hintf->desc.bNumEndpoints; i++) {        endp = &hintf->endpoint[i].desc;        if (usb_endpoint_is_bulk_in(endp))            bulk_in = endp->bEndpointAddress;        else if (usb_endpoint_is_bulk_out(endp))            bulk_out = endp->bEndpointAddress;    }    if (!(bulk_in && bulk_out)) {        retval = -ENODEV;        err("Unable to find endpoints, retval=%d", retval);        return retval;    }    else    {        dev->in = usb_rcvbulkpipe(dev->udev, bulk_in & USB_ENDPOINT_NUMBER_MASK);        dev->out= usb_sndbulkpipe(dev->udev, bulk_out & USB_ENDPOINT_NUMBER_MASK);    }    //fix bulk recv buffer size    dev->rx_urb_size = IPHETH_BUF_SIZE;    //dev->hard_mtu = IPHETH_BUF_SIZE;//need this?    //get hardware addr    retval = ipheth_get_macaddr(dev);    if (0 != retval)    {        err("Unable to get macaddr, retval=%d", retval);        return retval;    }    //carrier check:check the remote tethering enable or not.    mutex_init (&(local.local_mutex));    INIT_DELAYED_WORK(&(local.carrier_work), ipheth_carrier_check_work);    local.dev = dev;    return retval;}EXPORT_SYMBOL_GPL(ipheth_bind);static int ipheth_reset(struct usbnet *dev){    int retval = 0;//success    struct work_struct *work = NULL;    //Attention: this func's section should not be in "reset" function,    //I put it here because it still need to be called during the usbnet_open().    usb_set_interface(dev->udev, IPHETH_INTFNUM, IPHETH_ALT_INTFNUM);    ipheth_carrier_check_work(work);    return retval;}EXPORT_SYMBOL_GPL(ipheth_reset);static int ipheth_stop(struct usbnet *dev){    mutex_lock(&(local.local_mutex));    cancel_delayed_work_sync(&local.carrier_work);    mutex_unlock(&(local.local_mutex));    return 0;}EXPORT_SYMBOL_GPL(ipheth_stop);int ipheth_rx_fixup(struct usbnet *dev, struct sk_buff *skb){    skb_pull(skb, IPHETH_IP_ALIGN);    return 1;}EXPORT_SYMBOL_GPL(ipheth_rx_fixup);static const struct driver_info ipheth_info = {    .description =  "ipheth device",    .flags =    FLAG_ETHER | FLAG_NO_SETINT,    .status =   ipheth_status,    .bind =     ipheth_bind,    .reset =    ipheth_reset,    .stop =     ipheth_stop,    .rx_fixup = ipheth_rx_fixup,};/*-------------------------------------------------------------------------*/static struct usb_device_id ipheth_table[] = {    { USB_DEVICE_AND_INTERFACE_INFO(        USB_VENDOR_APPLE, USB_PRODUCT_IPHONE,        IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,        IPHETH_USBINTF_PROTO),        .driver_info = (unsigned long) &ipheth_info,},    { USB_DEVICE_AND_INTERFACE_INFO(        USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_3G,        IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,        IPHETH_USBINTF_PROTO),        .driver_info = (unsigned long) &ipheth_info,},    { USB_DEVICE_AND_INTERFACE_INFO(        USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_3GS,        IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,        IPHETH_USBINTF_PROTO),        .driver_info = (unsigned long) &ipheth_info,},    { USB_DEVICE_AND_INTERFACE_INFO(        USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_4,        IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,        IPHETH_USBINTF_PROTO),        .driver_info = (unsigned long) &ipheth_info,},    { USB_DEVICE_AND_INTERFACE_INFO(        USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_4_VZW,        IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,        IPHETH_USBINTF_PROTO),        .driver_info = (unsigned long) &ipheth_info,},    { USB_DEVICE_AND_INTERFACE_INFO(        USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_4S,        IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,        IPHETH_USBINTF_PROTO),        .driver_info = (unsigned long) &ipheth_info,},    { USB_DEVICE_AND_INTERFACE_INFO(        USB_VENDOR_APPLE, USB_PRODUCT_IPAD,        IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,        IPHETH_USBINTF_PROTO),        .driver_info = (unsigned long) &ipheth_info,},    { USB_DEVICE_AND_INTERFACE_INFO(        USB_VENDOR_APPLE, USB_PRODUCT_IPAD_MINI,        IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,        IPHETH_USBINTF_PROTO),        .driver_info = (unsigned long) &ipheth_info,},    { USB_DEVICE_AND_INTERFACE_INFO(        USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_5,        IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,        IPHETH_USBINTF_PROTO),        .driver_info = (unsigned long) &ipheth_info,},    { }};MODULE_DEVICE_TABLE(usb, ipheth_table);static struct usb_driver ipheth_driver = {    .name =     "ipheth",    .id_table = ipheth_table,    .probe =    usbnet_probe,    .disconnect =   usbnet_disconnect,    .suspend =  usbnet_suspend,    .resume =   usbnet_resume,};module_usb_driver(ipheth_driver);MODULE_AUTHOR("Walker Wei");MODULE_DESCRIPTION("Apple iPhone USB Ethernet driver");MODULE_LICENSE("GPL");

思路

android使用的usb tethering是基于Rndis的，一个Microsoft提出的usb tethering协议，它的结构是Rndis协议层+usb net，而usb net正是一个封装了USB networking的架构，将usb设备虚拟成Ethernet adapters。
usb net应该比较稳定了，因为不但Rndis使用，其他的一些usb net adapter产品，如亚信的AX88179、AX88772B等也都是基于usb net来做。
因此，本次的修改就是将原有的ipheth移植到usb net上，变成ipheth+usb net的形势，经测试，稳定多了，尤其是大量数据传输的时候。

当前的code只是测试版本，还有很多优化的空间，后续再更新。