在修改 tx_delay , rx_delay 需要在dts 中配置，每次都要重新再烧写过！ 所以在调试时需要耗费很多气力。只要修改一下原本的驱动，就可以无需另外的工具，就可以进行的调试
驱动位置 lichee/linux-5.4/drivers/net/ethernet/allwinner/sunxi-gmac.c
原代码
static ssize_t mii_write_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct net_device *ndev = NULL;
struct geth_priv *priv = NULL;
int ret = 0;
u16 reg, addr, val;
char *ptr;
ptr = (char *)buf;
if (dev == NULL) {
pr_err("Argment is invalid\n");
return count;
}
ndev = dev_get_drvdata(dev);
if (ndev == NULL) {
pr_err("Net device is null\n");
return count;
}
priv = netdev_priv(ndev);
if (priv == NULL) {
pr_err("geth_priv is null\n");
return count;
}
if (!netif_running(ndev)) {
pr_warn("eth is down!\n");
return count;
}
ret = sunxi_parse_write_str(ptr, &addr, ®, &val);
if (ret)
return ret;
priv->mii_reg.reg = reg;
priv->mii_reg.addr = addr;
priv->mii_reg.value = val;
return count;
}
攸改过后
static ssize_t mii_write_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct net_device *ndev = NULL;
struct geth_priv *priv = NULL;
int ret = 0;
u16 reg, addr, val;
char *ptr;
ptr = (char *)buf;
if (dev == NULL) {
pr_err("Argment is invalid\n");
return count;
}
ndev = dev_get_drvdata(dev);
if (ndev == NULL) {
pr_err("Net device is null\n");
return count;
}
priv = netdev_priv(ndev);
if (priv == NULL) {
pr_err("geth_priv is null\n");
return count;
}
if (!netif_running(ndev)) {
pr_warn("eth is down!\n");
return count;
}
ret = sunxi_parse_write_str(ptr, &addr, ®, &val);
if (ret)
return ret;
if((2 == reg) || (3 == reg))
{
u32 clk_value;
u8 tdelay;
u8 rdelay;
clk_value = readl(priv->base_phy);
tdelay = (clk_value >> 10) & 0x07;
rdelay = (clk_value >> 5) & 0x1f;
printk("gmac delay read tx--> %x , rx--> %x \n", tdelay, rdelay);
if(2 == reg)
{
tdelay = (val & 0x07);
}
else
{
rdelay = (val & 0x1f);
}
printk("gmac delay write tx--> %x , rx--> %x \n", tdelay, rdelay);
clk_value &= ~((0x07 << 10)| (0x1F << 5));
clk_value |= ((tdelay << 10) | (rdelay << 5));
writel(clk_value, priv->base_phy);
}
priv->mii_reg.reg = reg;
priv->mii_reg.addr = addr;
priv->mii_reg.value = val;
return count;
}
使用方式如下：
先使用 ifconfig eth0 192.168.1.100 ，啟动 gmac 驱动
使用下面命令，进行 tx_delay 修改，3 个参数 , 第一个随便设，第二个需设置 2 , 第三个為 tx_delay 设置值，范围 0x0 ~ 0x7
root@TinaLinux:/# echo 0 2 3 > /sys/devices/platform/soc@3000000/4500000.eth/mii_write
[ 66.901376] gmac delay read tx--> 2 , rx--> d
[ 66.911086] gmac delay write tx--> 3 , rx--> d
root@TinaLinux:/# echo 0 2 5 > /sys/devices/platform/soc@3000000/4500000.eth/mii_write
[ 92.944996] gmac delay read tx--> 3 , rx--> d
[ 92.954582] gmac delay write tx--> 5 , rx--> d
使用下面命令，进行 rx_delay 修改，3 个参数 , 第一个随便设，第二个需设置 3 , 第三个為 rx_delay 设置值，范围 0x0 ~ 0x1f , 输入需要使用 16 进位
root@TinaLinux:/# echo 0 3 a > /sys/devices/platform/soc@3000000/4500000.eth/mi_write
[ 108.317230] gmac delay read tx--> 5 , rx--> d
[ 108.327034] gmac delay write tx--> 5 , rx--> a
root@TinaLinux:/# echo 0 3 1c > /sys/devices/platform/soc@3000000/4500000.eth/mii_write
[ 120.347615] gmac delay read tx--> 5 , rx--> a
[ 120.357371] gmac delay write tx--> 5 , rx--> 1c
root@TinaLinux:/# echo 0 3 1c > /sys/devices/platform/soc@3000000/4500000.eth/mii_write
[ 126.976849] gmac delay read tx--> 5 , rx--> 1c
[ 126.986301] gmac delay write tx--> 5 , rx--> 1c
测试时先使用外机 ping d1s ，调整 rx_delay 值后，使用 ifconfig 查看 rx_byte 及 crc 值，看是否有正常接收，并且无 crc 。 找出某一区间都正常，例如 4 ~ c 都是正常的！ 此时将 rx_delay 设置在 8 。
rx_delay 设置后，在用 d1s ping 外机，调整 tx_delay 值，看在什么区间可以正常 ping 不丢包， 一样取中间值
