TP-LINK TG-3468 PCIe Gigabit Adapter

TP-LINK TG-3468 is a cheap and totally fine Gigabit network card from TP-Link which is powered by a Realtek chip. This network adapter works with the r8169 kernel module. Technically it has the draw-back of very little on-board memory for offloading network traffic; there's just 4K non-prefetchable and 16K prefetchable memory. In practice it does not matter unless you plan on using it on 2002-area hardware, any modern or older CPU can generate more tha enough interrupts to sustain gigabit traffic on multiple cards just fine.

[   15.330357] r8169 0000:03:00.0 eth1: RTL8168e/8111e at 0xffffc90010fc0000, c4:6e:1f:05:08:02, XID 0c200000 IRQ 39

These cards use one (x1) PCI Express v2 lane.

Technical details

lspci:

03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06)
        Subsystem: Device 7470:3468
        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 39
        Region 0: I/O ports at c000 [size=256]
        Region 2: Memory at fe800000 (64-bit, non-prefetchable) [size=4K]
        Region 4: Memory at d0800000 (64-bit, prefetchable) [size=16K]
        Capabilities: [40] Power Management version 3
                Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=375mA PME(D0+,D1+,D2+,D3hot+,D3cold+)
                Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
        Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
                Address: 00000000fee0f00c  Data: 4123
        Capabilities: [70] Express (v2) Endpoint, MSI 01
                DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <512ns, L1 <64us
                        ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset-
                DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
                        RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
                        MaxPayload 128 bytes, MaxReadReq 4096 bytes
                DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
                LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 <512ns, L1 <64us
                        ClockPM+ Surprise- 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-
                DevCap2: Completion Timeout: Not Supported, TimeoutDis+, LTR-, OBFF Not Supported
                DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-, LTR-, OBFF Disabled
                LnkCtl2: Target Link Speed: 2.5GT/s, EnterCompliance- SpeedDis-
                         Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
                         Compliance De-emphasis: -6dB
                LnkSta2: Current De-emphasis Level: -6dB, EqualizationComplete-, EqualizationPhase1-
                         EqualizationPhase2-, EqualizationPhase3-, LinkEqualizationRequest-
        Capabilities: [b0] MSI-X: Enable- Count=4 Masked-
                Vector table: BAR=4 offset=00000000
                PBA: BAR=4 offset=00000800
        Capabilities: [d0] Vital Product Data
                Unknown small resource type 05, will not decode more.
        Capabilities: [100 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- NonFatalErr-
                CEMsk:  RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr+
                AERCap: First Error Pointer: 00, GenCap+ CGenEn- ChkCap+ ChkEn-
        Capabilities: [140 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=01
                        Status: NegoPending- InProgress-
        Capabilities: [160 v1] Device Serial Number a7-23-00-00-68-4c-e0-00
        Kernel driver in use: r8169
        Kernel modules: r8169

See Also

• Realtek Network Products. Some on-board Realtek network adapters using the r8169 stall out with a (r8169): transmit queue 0 timed out message in the kernel ring buffer if TCO offloading is enabled (You can turn TCO offloading off with ethtool like ethtool -K enp6s0 tso off depending on what your interface is named). This does not apply to any PCIe network card with a Realtek chip we are aware of, but it's a fairly common problem with motherboards using the same Realtek chip cards like the TP-LINK TG-3468 use.