PowerEdge：系统可能未记录降级的 PCIe 链路

由于 PCIe 链路降级，服务器可能会遇到性能问题，但不会将其记录在 LC 或 SEL 中。在这些情况下，请参阅操作系统以检查意外降级的 PCIe 链路。

BIOS 包括上行和下行上对意外 PCIe 链路降级的检查，但在某些情况下，BIOS 检查后可能会发生这种情况，因此不会记录。

使用操作系统工具查看协商的 PCIe 链路速度。

示例摘录自 lspci -vvv 基于 Linux 的操作系统的输出：

0001:64:00.0 PCI bridge: Broadcom / LSI PEX890xx PCIe Gen 5 Switch (rev b0) (prog-if 00 [Normal decode])
    Subsystem: Dell PEX890xx PCIe Gen 5 Switch
    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
    NUMA node: 1
    Bus: primary=64, secondary=65, subordinate=6a, sec-latency=0
    I/O behind bridge: 0000f000-00000fff [disabled] [32-bit]
    Memory behind bridge: db000000-db2fffff [size=3M] [32-bit]
    Prefetchable memory behind bridge: 2e0000000000-2eafffffffff [size=704G] [32-bit]
    Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR-
    BridgeCtl: Parity+ SERR+ NoISA- VGA- VGA16- MAbort- >Reset- FastB2B-
        PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn-
    Capabilities: [40] Power Management version 3
        Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
        Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
    Capabilities: [68] Express (v2) Upstream Port, MSI 00
        DevCap:    MaxPayload 2048 bytes, PhantFunc 0
            ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ SlotPowerLimit 0W
        DevCtl:    CorrErr+ NonFatalErr+ FatalErr+ UnsupReq+
            RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
            MaxPayload 256 bytes, MaxReadReq 128 bytes
        DevSta:    CorrErr- NonFatalErr- FatalErr- UnsupReq- AuxPwr- TransPend-
        LnkCap:    Port #200, Speed 32GT/s, Width x16, ASPM L0s L1, Exit Latency L0s <4us, L1 <32us
            ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+
        LnkCtl:    ASPM Disabled; Disabled- CommClk-
            ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
        LnkSta:    Speed 16GT/s (downgraded), Width x16
            TrErr- Train- SlotClk- DLActive- BWMgmt- ABWMgmt-
        DevCap2: Completion Timeout: Not Supported, TimeoutDis- NROPrPrP- LTR-
             10BitTagComp+ 10BitTagReq- OBFF Not Supported, ExtFmt- EETLPPrefix+, MaxEETLPPrefixes 4
             EmergencyPowerReduction Not Supported, EmergencyPowerReductionInit-
             FRS-
             AtomicOpsCap: Routing+
        DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis- LTR- 10BitTagReq- OBFF Disabled,
             AtomicOpsCtl: EgressBlck-
        LnkCap2: Supported Link Speeds: 2.5-32GT/s, Crosslink+ Retimer+ 2Retimers+ DRS-
        LnkCtl2: Target Link Speed: 32GT/s, EnterCompliance- SpeedDis-
             Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
             Compliance Preset/De-emphasis: -6dB de-emphasis, 0dB preshoot
        LnkSta2: Current De-emphasis Level: -6dB, EqualizationComplete+ EqualizationPhase1+
             EqualizationPhase2+ EqualizationPhase3+ LinkEqualizationRequest-
             Retimer- 2Retimers- CrosslinkRes: unsupported
    Capabilities: [b0] Subsystem: Dell PEX890xx PCIe Gen 5 Switch
    Capabilities: [e0] Vendor Specific Information: Len=20 <?>
    Capabilities: [100 v1] Device Serial Number 00-80-5e-72-6f-30-7d-18
    Capabilities: [fb4 v1] Vendor Specific Information: ID=0000 Rev=0 Len=008 <?>
    Capabilities: [10c v1] Secondary PCI Express
        LnkCtl3: LnkEquIntrruptEn- PerformEqu-
        LaneErrStat: 0
    Capabilities: [150 v1] Virtual Channel
        Caps:    LPEVC=0 RefClk=100ns PATEntryBits=1
        Arb:    Fixed- WRR32- WRR64- WRR128-
        Ctrl:    ArbSelect=Fixed
        Status:    InProgress-
        VC0:    Caps:    PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
            Arb:    Fixed+ WRR32- WRR64- WRR128- TWRR128- WRR256-
            Ctrl:    Enable+ ID=0 ArbSelect=Fixed TC/VC=ff
            Status:    NegoPending- InProgress-
    Capabilities: [1e0 v1] Vendor Specific Information: ID=0001 Rev=2 Len=010 <?>
    Capabilities: [250 v1] Physical Layer 16.0 GT/s <?>
    Capabilities: [280 v1] Extended Capability ID 0x2a
    Capabilities: [180 v1] Lane Margining at the Receiver <?>
    Capabilities: [1d0 v1] Data Link Feature <?>
    Capabilities: [1f0 v1] Advanced Error Reporting
        UESta:    DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
        UEMsk:    DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt+ RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
        UESvrt:    DLP+ SDES+ TLP+ FCP+ CmpltTO+ CmpltAbrt+ UnxCmplt- RxOF+ MalfTLP+ ECRC+ UnsupReq- ACSViol-
        CESta:    RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr-
        CEMsk:    RxErr+ BadTLP+ BadDLLP+ Rollover+ Timeout+ AdvNonFatalErr+
        AERCap:    First Error Pointer: 1f, ECRCGenCap+ ECRCGenEn- ECRCChkCap+ ECRCChkEn-
            MultHdrRecCap- MultHdrRecEn- TLPPfxPres- HdrLogCap-
        HeaderLog: 00000000 00000000 00000000 00000000
    Capabilities: [220 v1] Vendor Specific Information: ID=2000 Rev=1 Len=020 <?>
    Kernel driver in use: pcieport