kernel MAC和PHY

步骤一，ifconfig -a 查询网卡

能识别到网卡

ifconfig -a
 ——————————————————————
eth0      Link encap:Ethernet  HWaddr 96:6f:9c:8b:a6:12  
......
lo        Link encap:Local Loopback  
......

步骤二，重启网卡

目的是走一遍网卡驱动流程。报错了

ifconfig eth0 down
ifconfig eth0 up
 ——————————————————————
[   21.772399] Generic PHY stmmac-0:00: attached PHY driver [Generic PHY] (mii_bus:phy_addr=stmmac-0:00, irq=POLL)
[   21.896404] rk_gmac-dwmac fe2a0000.ethernet: Failed to reset the dma
[   21.896452] rk_gmac-dwmac fe2a0000.ethernet eth0: stmmac_hw_setup: DMA engine initialization failed
[   21.896464] rk_gmac-dwmac fe2a0000.ethernet eth0: stmmac_open: Hw setup failed
SIOCSIFFLAGS: Device or resource busy

说明phy初始化是成功的，MAC网卡初始化失败。

步骤三，对比南瑞自己的板子，因为他的网卡驱动正常

使用南瑞自己的内核+设备树和根文件系统，启动系统后有如下打印

[   11.278840] rk_gmac-dwmac fe2a0000.ethernet: Looking up phy-supply from device tree
[   11.278872] rk_gmac-dwmac fe2a0000.ethernet: Looking up phy-supply property in node /ethernet@fe2a0000 failed
[   11.278907] rk_gmac-dwmac fe2a0000.ethernet: no regulator found
[   11.279020] rk_gmac-dwmac fe2a0000.ethernet: clock input or output? (output).
[   11.279053] rk_gmac-dwmac fe2a0000.ethernet: TX delay(0x3c).
[   11.279082] rk_gmac-dwmac fe2a0000.ethernet: RX delay(0x2f).
[   11.279115] rk_gmac-dwmac fe2a0000.ethernet: integrated PHY? (no).
[   11.284221] rk_gmac-dwmac fe2a0000.ethernet: init for RGMII
[   11.284564] rk_gmac-dwmac fe2a0000.ethernet: User ID: 0x30, Synopsys ID: 0x51
[   11.284636] rk_gmac-dwmac fe2a0000.ethernet:         DWMAC4/5
[   11.284664] rk_gmac-dwmac fe2a0000.ethernet: DMA HW capability register supported
[   11.284689] rk_gmac-dwmac fe2a0000.ethernet: RX Checksum Offload Engine supported
[   11.284712] rk_gmac-dwmac fe2a0000.ethernet: TX Checksum insertion supported
[   11.284735] rk_gmac-dwmac fe2a0000.ethernet: Wake-Up On Lan supported
[   11.284758] rk_gmac-dwmac fe2a0000.ethernet: TSO supported
[   11.284781] rk_gmac-dwmac fe2a0000.ethernet: Enable RX Mitigation via HW Watchdog Timer
[   11.284806] rk_gmac-dwmac fe2a0000.ethernet: TSO feature enabled
[   11.815111] rk_gmac-dwmac fe2a0000.ethernet ethdbg: renamed from eth1
[   11.874706] rk_gmac-dwmac fe2a0000.ethernet ethdbg: No Safety Features support found
[   11.874742] rk_gmac-dwmac fe2a0000.ethernet ethdbg: IEEE 1588-2008 Advanced Timestamp supported
[   11.875069] rk_gmac-dwmac fe2a0000.ethernet ethdbg: registered PTP clock
[   14.920473] rk_gmac-dwmac fe2a0000.ethernet ethdbg: Link is Up - 100Mbps/Full - flow control rx/tx
[   11.285552] libphy: stmmac: probed

正常可以使用，但关闭后无法重启

ifconfig ethdbg down
ifconfig ethdbg up    # 无法重启网卡，同样的错误
——————————————————————
SIOCSIFFLAGS: Device or resource busy

步骤四，尝试读写phy寄存器

查阅rk官方文档，可知系统启动后可以读写phy的寄存器，如下

根据返回值，说明可以正常读到phy的寄存器值，并且寄存器值基本正常，所以phy芯片的驱动是正常的，网卡无法使用可以确定是MAC驱动错误。

root@rk3568:~# cat /sys/bus/mdio_bus/devices/stmmac-0\:00/phy_registers 
 0: 0x1940
 1: 0x7949
 2: 0x937c
 3: 0x4032
 4: 0x1e1
 5: 0x0
 6: 0x6
 7: 0x2001
 8: 0x0
 9: 0x200
10: 0x0
11: 0x0
12: 0x0
13: 0x0
14: 0x0
15: 0x2000
16: 0x0
17: 0x0
18: 0x0
19: 0x0
20: 0xc090
21: 0x7c13
22: 0x489b
23: 0x0
24: 0x8000
25: 0x0
26: 0x0
27: 0x2f
28: 0x0
29: 0x1101
30: 0x0
31: 0x0

步骤四，尝试将复位引脚注释掉

将几个snps属性注释掉

&gmac0 {
    phy-mode = "rgmii";
    clock_in_out = "output";
    assigned-clocks = <&cru SCLK_GMAC0_RX_TX>, <&cru SCLK_GMAC0>;
    assigned-clock-parents = <&cru SCLK_GMAC0_RGMII_SPEED>;
    assigned-clock-rates = <0>, <125000000>;
    
    // snps,reset-gpio = <&gpio0 RK_PB7 GPIO_ACTIVE_LOW>;
    // snps,reset-active-low;
    // /* Reset time is 20ms, 100ms for rtl8211f */
    // snps,reset-delays-us = <0 20000 100000>;
    pinctrl-names = "default";
    pinctrl-0 = <&gmac0_miim
             &gmac0_tx_bus2
             &gmac0_rx_bus2
             &gmac0_rgmii_clk
             &gmac0_rgmii_bus>;
    tx_delay = <0x3c>;
    rx_delay = <0x2f>;
    phy-handle = <&rgmii_phy0>;
    status = "okay";
};

烧录之后重启，在uboot命令行下使用网卡后，比如ping命令，启动内核时网卡会有以下打印，说明正常（后续查明这个正常的原因是内核继承了uboot初始化网卡的硬件条件，导致内核可以使用网卡）。但是重启网卡时同样报错。

[    9.330236] Generic PHY stmmac-0:00: attached PHY driver [Generic PHY] (mii_bus:phy_addr=stmmac-0:00, irq=POLL)
[    9.352653] dwmac4: Master AXI performs any burst length
[    9.352717] rk_gmac-dwmac fe2a0000.ethernet eth0: No Safety Features support found
[    9.352755] rk_gmac-dwmac fe2a0000.ethernet eth0: IEEE 1588-2008 Advanced Timestamp supported
[    9.366724] rk_gmac-dwmac fe2a0000.ethernet eth0: registered PTP clock
[    9.367518] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[   10.380895] rk_gmac-dwmac fe2a0000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
[   10.380988] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready

而且在上电后直接启动内核而不使用uboot网卡功能时，直接报错。
说明注释调复位引脚不能解决问题

步骤五，将错误log复制到kernel源码中搜索

得到以下函数调用

module_platform_driver(rk_gmac_dwmac_driver);
——rk_gmac_dwmac_driver.probe = rk_gmac_probe()
————stmmac_dvr_probe()
——————stmmac_hw_init()
————————stmmac_hwif_init()
——————————entry = &stmmac_hw[i];    // stmmac_hw[] = { {.dma = &dwmac410_dma_ops,.....} }    const struct stmmac_dma_ops dwmac410_dma_ops = { .reset = dwmac4_dma_reset,..... }
——————————mac->dma = mac->dma ? : entry->dma;
——————ndev->netdev_ops = &stmmac_netdev_ops
————————stmmac_netdev_ops.ndo_open = stmmac_open()
——————————stmmac_init_phy()
——————————stmmac_hw_setup()
——————————stmmac_init_dma_engine()
————————————stmmac_reset()
——————————————dwmac4_dma_reset()
————————————————if (limit < 0)    return -EBUSY;          //#define	EBUSY		16	/* Device or resource busy */
———————————— [   12.608163] CXY ################# stmmac_reset():ret[-16]    
———————————— "Failed to reset the dma"
——————————  "DMA engine initialization failed"
————————"Hw setup failed"

步骤六，取消DMA_RESET

drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c，在writel之前return 0，直接取消这个复位操作，修改之后如下

int dwmac4_dma_reset(void __iomem *ioaddr)
{
	u32 value = readl(ioaddr + DMA_BUS_MODE);
	int limit;

	/* DMA SW reset */
	value |= DMA_BUS_MODE_SFT_RESET;
	return 0;
	writel(value, ioaddr + DMA_BUS_MODE);
	limit = 10;
	while (limit--) {
		if (!(readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET))
			break;
		mdelay(10);
	}

	if (limit < 0)
		return -EBUSY;

	return 0;
}

步骤七，测试

启动内核，得到内核启动日志
驱动正常了

[    0.661549] rk_gmac-dwmac fe2a0000.ethernet: Looking up phy-supply from device tree
[    0.661566] rk_gmac-dwmac fe2a0000.ethernet: Looking up phy-supply property in node /ethernet@fe2a0000 failed
[    0.661593] rk_gmac-dwmac fe2a0000.ethernet: no regulator found
[    0.661618] rk_gmac-dwmac fe2a0000.ethernet: clock input or output? (output).
[    0.661636] rk_gmac-dwmac fe2a0000.ethernet: TX delay(0x3c).
[    0.661651] rk_gmac-dwmac fe2a0000.ethernet: RX delay(0x2f).
[    0.661672] rk_gmac-dwmac fe2a0000.ethernet: integrated PHY? (no).
[    0.666730] rk_gmac-dwmac fe2a0000.ethernet: init for RGMII
[    0.667036] rk_gmac-dwmac fe2a0000.ethernet: User ID: 0x30, Synopsys ID: 0x51
[    0.667064] rk_gmac-dwmac fe2a0000.ethernet:         DWMAC4/5
[    0.667083] rk_gmac-dwmac fe2a0000.ethernet: DMA HW capability register supported
[    0.667098] rk_gmac-dwmac fe2a0000.ethernet: RX Checksum Offload Engine supported
[    0.667110] rk_gmac-dwmac fe2a0000.ethernet: TX Checksum insertion supported
[    0.667122] rk_gmac-dwmac fe2a0000.ethernet: Wake-Up On Lan supported
[    0.667165] rk_gmac-dwmac fe2a0000.ethernet: TSO supported
[    0.667180] rk_gmac-dwmac fe2a0000.ethernet: Enable RX Mitigation via HW Watchdog Timer
[    0.667196] rk_gmac-dwmac fe2a0000.ethernet: TSO feature enabled
[   23.613091] rk_gmac-dwmac fe2a0000.ethernet eth0: No Safety Features support found
[   23.613129] rk_gmac-dwmac fe2a0000.ethernet eth0: IEEE 1588-2008 Advanced Timestamp supported
[   23.618581] rk_gmac-dwmac fe2a0000.ethernet eth0: registered PTP clock
[   27.686915] rk_gmac-dwmac fe2a0000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx

ifconfig    # 网卡也出来了

步骤八，测试ping命令

ifconfig eth0 192.168.11
ping 192.168.1.10
————————————————————
ping: sendmsg: Operation not permitted

出现Operation not permitted错误

tftp -g -r uboot.img 192.168.1.10
tftp: sendto: Operation not permitted

同样出现Operation not permitted错误

步骤九，关闭iptables

使用一下命令关闭防火墙，网络功能就都可以使用了

iptables -P OUTPUT ACCEPT
iptables -P INPUT ACCEPT