linux+arm 网卡故障调试：ethtool&phy寄存器读写

两个工具一个是ethtool工具，一个是源码编译的可以读phy寄存器的工具phyreg。两者结合使用，事半功倍。

ethtool 可以查看和设置网卡的工作状态，比如查看设置网卡的链接 自协商，10/100/1000M,双工半双工的工作状态。

ethtool的交叉编译工具，见个人博客文章：http://blog.csdn.net/vc66vcc/article/details/52398864

phyreg 可以读写phy的任意寄存器。相关源码如下

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 


#define reteck(ret)     \
        if(ret < 0){    \
            printf("%m! \"%s\" : line: %d\n", __func__, __LINE__);   \
            goto lab;   \
        }

#define help() \
    printf("mdio:\n");                  \
    printf("read operation: mdio reg_addr\n");          \
    printf("write operation: mdio reg_addr value\n");    \
    printf("For example:\n");            \
    printf("mdio eth0 1\n");             \
    printf("mdio eth0 0 0x12\n\n");      \
    exit(0);

int sockfd;

int main(int argc, char *argv[]){
        
    if(argc == 1 || !strcmp(argv[1], "-h")){
        help();
    }
    
    struct mii_ioctl_data *mii = NULL;
    struct ifreq ifr;
    int ret;

    memset(&ifr, 0, sizeof(ifr));
    strncpy(ifr.ifr_name, argv[1], IFNAMSIZ - 1);

    sockfd = socket(PF_LOCAL, SOCK_DGRAM, 0);
    reteck(sockfd);

    //get phy address in smi bus
    ret = ioctl(sockfd, SIOCGMIIPHY, &ifr);
    reteck(ret);

    mii = (struct mii_ioctl_data*)&ifr.ifr_data;

    if(argc == 3){

        mii->reg_num    = (uint16_t)strtoul(argv[2], NULL, 0);
        
        ret = ioctl(sockfd, SIOCGMIIREG, &ifr);
        reteck(ret);
    
        printf("read phy addr: 0x%x  reg: 0x%x   value : 0x%x\n\n", mii->phy_id, mii->reg_num, mii->val_out);
	}else if(argc == 4){

        mii->reg_num    = (uint16_t)strtoul(argv[2], NULL, 0);
        mii->val_in     = (uint16_t)strtoul(argv[3], NULL, 0);

        ret = ioctl(sockfd, SIOCSMIIREG, &ifr);
        reteck(ret);

        printf("write phy addr: 0x%x  reg: 0x%x  value : 0x%x\n\n", mii->phy_id, mii->reg_num, mii->val_in);
    }

lab:
    close(sockfd);
    return 0;
}