1、以太網（ethernet）的調試：
Rk默認已經添加了mac驅動。網卡分爲兩個層次：MAC+PHY
一般說來，MAC就是網絡控制器，如果該驅動OK，就能直接看到ifconfig信息；
PHY是物理層，負責發送和傳輸的底層，如果PHY發生問題，ifconfig同樣有信息，只有up時纔會連接PHY，down時斷開連接。
MAC和PHY通過MII接口傳輸以太網數據，通過MDIO接口訪問PHY的配置寄存器。 PHY連不上第一可能是硬件問題，拿給做硬件的，首先檢查一下供電是否正常（最關鍵），然後檢查一下PHY所有信號是否都很正常（一般連接對了都沒啥問題），
Adb通過 ifconfig -a命令可以查看是否註冊了網卡設備eth0
rk3288:/ # ifconfig -a
sit0 Link encap:IPv6-in-IPv4
NOARP MTU:1480 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 TX bytes:0
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope: Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 TX bytes:0
eth0 Link encap:Ethernet HWaddr 46:50:6f:9d:8c:82
inet addr:192.168.2.27 Bcast:192.168.2.255 Mask:255.255.255.0
inet6 addr: fe80::4450:6fff:fe9d:8c82/64 Scope: Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:908 errors:0 dropped:0 overruns:0 frame:0
TX packets:99 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:72432 TX bytes:12712
Interrupt:38
rk3288:/ #
我這裏調試的是：Rk3288_Android7.1，kernel版本是4.4， 代碼位置在drivers/net/ethernet/stmicro/stmmac/.
Dts配置：
--- a/arch/arm/boot/dts/rk3288-evb.dtsi
+++ b/arch/arm/boot/dts/rk3288-evb.dtsi
ext_gmac: external-gmac-clock {
compatible = "fixed-clock";
clock-frequency = <125000000>; //1000M網用125M
clock-output-names = "ext_gmac";
#clock-cells = <0>;
};
&gmac {
// phy-supply = <&vcc_phy>; //原理圖phy的供電PHY_PMEB直接使用pmu的ldo腳， 所以這裏注掉，不需要再配置
phy-mode = "rgmii";
clock_in_out = "input";
snps,reset-gpio = <&gpio4 8 0>; //復位pin（參考原理圖）
snps,reset-active-low;
snps,reset-delays-us = <0 10000 50000>;
assigned-clocks = <&cru SCLK_MAC>;
assigned-clock-parents = <&ext_gmac>;
pinctrl-names = "default";
pinctrl-0 = <&rgmii_pins>;
tx_delay = <0x30>;
rx_delay = <0x10>;
max-speed = <1000>; //這裏配置最大的限速，1000就是可以達到1000M速度,100就是100M最大限速
status = "okay";
};
問題點總結：
1、萬用表量供電腳PHY_PME只有0.4v的供電。
分析：
Phy的供電腳使用pmu（rk808）的VSWOUT2腳（對照原理圖），注意dts添加對應pin的節點配置，這樣rk808驅動才能添加對應的寄存器設置，使該pin輸出3.3v供電：
--- a/arch/arm/boot/dts/rk3288-evb-android-rk808-hdmi.dts
+++ b/arch/arm/boot/dts/rk3288-evb-android-rk808-hdmi.dts
+ vcc_lan: SWITCH_REG2 {
+ regulator-always-on;
+ regulator-boot-on;
+ regulator-min-microvolt = <3300000>;
+ regulator-max-microvolt = <3300000>;
+ regulator-name = "vcc_lan";
+ regulator-state-mem {
+ regulator-off-in-suspend;
+ };
+ };
2、報錯rk_gmac-dwmac: probe of ff290000.ethernet failed with error -1。
分析：
dwmac-rk.c驅動的上電函數phy_power_on讀取不到phy-supply的有效ldo，直接返回-1報錯，就會無法正常識別到網卡設備eth0，需在驅動drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c中注掉phy_power_on的上下電操作，直接返回0即可。
static int phy_power_on(struct rk_priv_data *bsp_priv, bool enable)
{
/* struct regulator *ldo = bsp_priv->regulator;
int ret;
struct device *dev = &bsp_priv->pdev->dev;
if (!ldo) {
dev_err(dev, "no regulator found\n");
return -1;
}
if (enable) {
ret = regulator_enable(ldo);
if (ret)
dev_err(dev, "fail to enable phy-supply\n");
} else {
ret = regulator_disable(ldo);
if (ret)
dev_err(dev, "fail to disable phy-supply\n");
}
*/
return 0;
}
3、開機起來只識別到100M的速率，相關log打印：rk_gmac-dwmac ff290000.ethernet eth0: Link is Up - 100Mbps/Full - flow control off）
分析：
dts配置：
max-speed = <1000>; //這裏配置最大的限速
4、如果PHY的供電腳PHY_PMEB使用GPIO控制開關的話，dts部分還需要對照原理圖加上以下的GPIO的配置。
vcc_phy: vcc-phy-regulator {
compatible = "regulator-fixed";
enable-active-high;
gpio = <&gpio0 8 GPIO_ACTIVE_HIGH>;
pinctrl-names = "default";
pinctrl-0 = <ð_phy_pwr>;
regulator-name = "vcc_phy";
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
regulator-always-on;
regulator-boot-on;
};
& pinctrl {
eth_phy {
eth_phy_pwr: eth-phy-pwr {
rockchip,pins = <0 8 RK_FUNC_GPIO &pcfg_pull_none>;
};
};