如何获取（并学习有意义地解释）有关 Ubuntu 10.04 (Lucid) Linux 系统上 Wifi 子系统的非常低级的诊断信息？

Question

我深入研究了 NetworkManager（并从那里深入研究了 dbus 等）并确定了我正在使用的无线驱动程序（iwlagn）；但我确信只要我知道去哪里寻找，我就能学到更多东西。

如果您能提供教程、参考资料（在线或离线）或操作指南，我们将不胜感激。

（如果人们认为在 serverfault.com 或 superuser.com 上询问这个问题更好，请告诉我。）如果

您感兴趣，以下是 sudo lspci -vvxxx -s 04:0.0 返回的内容：

04:00.0 Network controller: Intel Corporation Wireless WiFi Link 5100
    Subsystem: Intel Corporation Device 1201
    Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
    Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
    Latency: 0, Cache Line Size: 64 bytes
    Interrupt: pin A routed to IRQ 32
    Region 0: Memory at f2c00000 (64-bit, non-prefetchable) [size=8K]
    Capabilities: [c8] Power Management version 3
        Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
        Status: D0 PME-Enable- DSel=0 DScale=0 PME-
    Capabilities: [d0] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable+
        Address: 00000000fee0100c  Data: 41b1
    Capabilities: [e0] Express (v1) Endpoint, MSI 00
        DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <512ns, L1 unlimited
            ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset+
        DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
            RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+ FLReset-
            MaxPayload 128 bytes, MaxReadReq 128 bytes
        DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
        LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 <128ns, L1 <32us
            ClockPM+ Suprise- LLActRep- BwNot-
        LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
            ExtSynch- ClockPM+ AutWidDis- BWInt- AutBWInt-
        LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
    Capabilities: [100] Advanced Error Reporting <?>
    Capabilities: [140] Device Serial Number 04-ed-3b-ff-ff-65-1e-00
    Kernel driver in use: iwlagn
    Kernel modules: iwlagn
00: 86 80 32 42 06 04 10 00 00 00 80 02 10 00 00 00
10: 04 00 c0 f2 00 00 00 00 00 00 00 00 00 00 00 00
20: 00 00 00 00 00 00 00 00 00 00 00 00 86 80 01 12
30: 00 00 00 00 c8 00 00 00 00 00 00 00 0a 01 00 00
40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0: 00 00 00 00 00 00 00 00 01 d0 23 c8 00 00 00 0d
d0: 05 e0 81 00 0c 10 e0 fe 00 00 00 00 b1 41 00 00
e0: 10 00 01 00 c0 8e 00 10 10 08 10 00 11 9c 06 00
f0: 40 01 11 10 00 00 00 00 00 00 00 00 00 00 00 00

Answer 1

首先，您应该在内核中启用802.11堆栈的调试输出。

其次，您应该在启用调试输出的情况下编译内核（或仅驱动程序模块）（CONFIG_IWLWIFI_DEBUG）。以下是 Kconfig 文件的摘录：

  To set a value, simply echo an 8-byte hex value to the same file:

      % echo 0x43fff > /sys/class/net/wlan0/device/debug_level

  You can find the list of debug mask values in:
      drivers/net/wireless/iwlwifi/iwl-debug.h

还有一些对 iwlagn 的 DebugFS 支持 (CONFIG_IWLWIFI_DEBUGFS)。

第三，如果您使用 WPA 或 802.11i（您应该），您可以终止 NetworkManager 并为 wpa_supplicant 创建您自己的配置文件（查看 README 到看看如何）。然后您可以使用 -dd 开关运行 wpa_supplicant 以打开其调试信息。