Re: rge(4) RTL8126 simple testing

From: Sean C. Farley <scf_at_FreeBSD.org>
Date: Thu, 05 Mar 2026 17:05:00 UTC
On Wed, 4 Mar 2026, Adrian Chadd wrote:

> That's all good to know; if the vendor driver / linux driver can't
> negotiate 2.5g then we can try poking realtek directly for help.
> They're more likely to help if reproducible in these drivers.
>
> -a

Just to make sure this is not lost:  Who does the poking and prodding? 
While I can do it, I have no idea where.  :)

Sean
-- 
scf@FreeBSD.org


> On Wed, 4 Mar 2026 at 13:02, Sean C. Farley <scf@freebsd.org> wrote:
>>
>> On Sat, 28 Feb 2026, Sean C. Farley wrote:
>>
>>> I recently upgraded my home network using a few BrosTrend 5Gb cards
>>> (RTL8126) with 14-STABLE (1eb2beb3686c) and the latest commit
>>> (3170b35) to the GitHub repo for if_rge.  It was either these cards or
>>> a couple of Intel X550-T2 cards, but less power and less heat were the
>>> deciding factors.
>>>
>>> For the most part, they seem to work very well, except that they
>>> cannot negotiate a 2500Base-T connection.  They can negotiate
>>> 1000baseT and 5000Base-T.  This was with two different cards
>>> connecting to two different devices.  If manually set, they will try
>>> for awhile than fall-back to 1000baseT.
>>>
>>> One other oddity is that rge0 has "ClockPM disabled", but I have not
>>> looked into that.
>>>
>>> The networking hardware:
>>> - 3 BrosTrend 5Gb NIC's[1]  (5Gb)
>>> - Zyxel NWA130BE[2]  (2.5Gb port)
>>> - TRENDnet TEG-S591[3]  (connected the NIC to its 10Gb port)
>>> - Nokia ONT XS-010X-Q[4]  (10Gb port)
>>>
>>> ifconfig:
>>> rge0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0
>>> mtu 1500
>>>       options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
>>>       capabilities=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
>>>        media: Ethernet autoselect (5000Base-T <full-duplex>)
>>>       status: active
>>>       supported media:
>>>               media autoselect
>>>               media 5000Base-T mediaopt full-duplex
>>>               media 5000Base-T
>>>               media 2500Base-T mediaopt full-duplex
>>>               media 2500Base-T
>>>               media 1000baseT mediaopt full-duplex
>>>               media 1000baseT
>>>               media 100baseTX mediaopt full-duplex
>>>               media 100baseTX
>>>               media 10baseT/UTP mediaopt full-duplex
>>>               media 10baseT/UTP
>>>       nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
>>>       drivername: rge0
>>> rge1: flags=1008943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST,LOWER_UP>
>>> metric 0 mtu 1500
>>>       options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
>>>       capabilities=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
>>>       media: Ethernet autoselect (5000Base-T <full-duplex>)
>>>       status: active
>>>       supported media:
>>>               media autoselect
>>>               media 5000Base-T mediaopt full-duplex
>>>               media 5000Base-T
>>>               media 2500Base-T mediaopt full-duplex
>>>               media 2500Base-T
>>>               media 1000baseT mediaopt full-duplex
>>>               media 1000baseT
>>>               media 100baseTX mediaopt full-duplex
>>>               media 100baseTX
>>>               media 10baseT/UTP mediaopt full-duplex
>>>               media 10baseT/UTP
>>>       nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
>>>       drivername: rge1
>>> rge2: flags=1008943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST,LOWER_UP>
>>> metric 0 mtu 1500
>>>       options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
>>>       capabilities=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
>>>       media: Ethernet Other (1000baseT <full-duplex>)
>>>       status: active
>>>       supported media:
>>>               media autoselect
>>>               media 5000Base-T mediaopt full-duplex
>>>               media 5000Base-T
>>>               media 2500Base-T mediaopt full-duplex
>>>               media 2500Base-T
>>>               media 1000baseT mediaopt full-duplex
>>>               media 1000baseT
>>>               media 100baseTX mediaopt full-duplex
>>>               media 100baseTX
>>>               media 10baseT/UTP mediaopt full-duplex
>>>               media 10baseT/UTP
>>>       nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
>>>       drivername: rge2
>>>
>>> pciconf:
>>> rge0@pci0:1:0:0:      class=0x020000 rev=0x01 hdr=0x00 vendor=0x10ec
>>> device=0x8126 subvendor=0x10ec subdevice=0x0123
>>>    vendor     = 'Realtek Semiconductor Co., Ltd.'
>>>    device     = 'RTL8126 5GbE Controller'
>>>    class      = network
>>>    subclass   = ethernet
>>>    bar   [10] = type I/O Port, range 32, base 0xe000, size 256, enabled
>>>    bar   [18] = type Memory, range 64, base 0xf7600000, size 65536, enabled
>>>    bar   [20] = type Memory, range 64, base 0xf7610000, size 16384, enabled
>>>    cap 01[40] = powerspec 3  supports D0 D1 D2 D3  current D0
>>>    cap 05[50] = MSI supports 1 message, 64 bit, vector masks enabled with 1
>>> message
>>>    cap 10[70] = PCI-Express 2 endpoint MSI 1 max data 256(512) RO
>>>                 max read 512
>>>                 link x1(x1) speed 8.0(8.0) ASPM disabled(L0s/L1) ClockPM
>>> disabled
>>>    cap 11[b0] = MSI-X supports 32 messages
>>>                 Table in map 0x20[0x0], PBA in map 0x20[0x800]
>>>    cap 03[d0] = VPD
>>>    ecap 0001[100] = AER 2 0 fatal 0 non-fatal 1 corrected
>>>    ecap 0002[148] = VC 1 max VC0
>>>    ecap 0003[170] = Serial 1 01000000684ce000
>>>    ecap 0019[180] = PCIe Sec 1 lane errors 0
>>>    ecap 0017[190] = TPH Requester 1
>>>    ecap 0018[21c] = LTR 1
>>>    ecap 001e[224] = L1 PM Substates 1
>>>    ecap 000b[234] = Vendor [1] ID 0002 Rev 4 Length 256
>>> rge1@pci0:4:0:0:      class=0x020000 rev=0x01 hdr=0x00 vendor=0x10ec
>>> device=0x8126 subvendor=0x10ec subdevice=0x0123
>>>    vendor     = 'Realtek Semiconductor Co., Ltd.'
>>>    device     = 'RTL8126 5GbE Controller'
>>>    class      = network
>>>    subclass   = ethernet
>>>    bar   [10] = type I/O Port, range 32, base 0xd000, size 256, enabled
>>>    bar   [18] = type Memory, range 64, base 0xf7500000, size 65536, enabled
>>>    bar   [20] = type Memory, range 64, base 0xf7510000, size 16384, enabled
>>>    cap 01[40] = powerspec 3  supports D0 D1 D2 D3  current D0
>>>    cap 05[50] = MSI supports 1 message, 64 bit, vector masks enabled with 1
>>> message
>>>    cap 10[70] = PCI-Express 2 endpoint MSI 1 max data 256(512) RO
>>>                 max read 512
>>>                 link x1(x1) speed 8.0(8.0) ASPM disabled(L0s/L1) ClockPM
>>> enabled
>>>    cap 11[b0] = MSI-X supports 32 messages
>>>                 Table in map 0x20[0x0], PBA in map 0x20[0x800]
>>>    cap 03[d0] = VPD
>>>    ecap 0001[100] = AER 2 0 fatal 0 non-fatal 0 corrected
>>>    ecap 0002[148] = VC 1 max VC0
>>>    ecap 0003[170] = Serial 1 01000000684ce000
>>>    ecap 0019[180] = PCIe Sec 1 lane errors 0
>>>    ecap 0017[190] = TPH Requester 1
>>>    ecap 0018[21c] = LTR 1
>>>    ecap 001e[224] = L1 PM Substates 1
>>>    ecap 000b[234] = Vendor [1] ID 0002 Rev 4 Length 256
>>> rge2@pci0:5:0:0:      class=0x020000 rev=0x01 hdr=0x00 vendor=0x10ec
>>> device=0x8126 subvendor=0x10ec subdevice=0x0123
>>>    vendor     = 'Realtek Semiconductor Co., Ltd.'
>>>    device     = 'RTL8126 5GbE Controller'
>>>    class      = network
>>>    subclass   = ethernet
>>>    bar   [10] = type I/O Port, range 32, base 0xc000, size 256, enabled
>>>    bar   [18] = type Memory, range 64, base 0xf7400000, size 65536, enabled
>>>    bar   [20] = type Memory, range 64, base 0xf7410000, size 16384, enabled
>>>    cap 01[40] = powerspec 3  supports D0 D1 D2 D3  current D0
>>>    cap 05[50] = MSI supports 1 message, 64 bit, vector masks enabled with 1
>>> message
>>>    cap 10[70] = PCI-Express 2 endpoint MSI 1 max data 256(512) RO
>>>                 max read 512
>>>                 link x1(x1) speed 8.0(8.0) ASPM disabled(L0s/L1) ClockPM
>>> enabled
>>>    cap 11[b0] = MSI-X supports 32 messages
>>>                 Table in map 0x20[0x0], PBA in map 0x20[0x800]
>>>    cap 03[d0] = VPD
>>>    ecap 0001[100] = AER 2 0 fatal 0 non-fatal 0 corrected
>>>    ecap 0002[148] = VC 1 max VC0
>>>    ecap 0003[170] = Serial 1 01000000684ce000
>>>    ecap 0019[180] = PCIe Sec 1 lane errors 0
>>>    ecap 0017[190] = TPH Requester 1
>>>    ecap 0018[21c] = LTR 1
>>>    ecap 001e[224] = L1 PM Substates 1
>>>    ecap 000b[234] = Vendor [1] ID 0002 Rev 4 Length 256
>>>
>>> Sean
>>>  1. https://www.brostrend.com/products/p2
>>>  2. https://www.zyxel.com/us/en-us/products/wireless/be11000-6-stream-wifi-7-triple-radio-nebulaflex-access-point-nwa130be
>>>  3. https://www.trendnet.com/products/2_5g-10g-switches/9-port-multi-gig-switch-TEG-S591-v1
>>>  4. https://www.nokia.com/asset/210704/
>>
>> I have spent awhile trying different things yet cannot get these to work
>> at 2.5G.  The Realtek vendor driver cannot negotiate at 2.5G nor can
>> Linux 6.18 (Arch Linux).
>>
>> Important details:
>> - FreeBSD dmesg chip rev: RTL8126_2 (0x64a00000)
>> - Forcing them to advertise only at 2.5G on Linux using ethtool results
>>    in the NIC never connecting to the link partner.
>> - Register dump from ethtool shows an interesting message:
>>    Unknown RealTek chip (TxConfig: 0x67a00f00)
>> - lspci snippets:
>>    05:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8126 5GbE Controller [10ec:8126] (rev 01)
>>          Subsystem: Realtek Semiconductor Co., Ltd. Device [10ec:0123]
>>    ...
>>
>>    05:00.0 0200: 10ec:8126 (rev 01)
>>          Subsystem: 10ec:0123
>>          Flags: bus master, fast devsel, latency 0, IRQ 19
>>          I/O ports at c000 [size=256]
>>          Memory at f7400000 (64-bit, non-prefetchable) [size=64K]
>>          Memory at f7410000 (64-bit, non-prefetchable) [size=16K]
>>          Capabilities: [40] Power Management version 3
>>          Capabilities: [50] MSI: Enable- Count=1/1 Maskable+ 64bit+
>>          Capabilities: [70] Express Endpoint, IntMsgNum 1
>>          Capabilities: [b0] MSI-X: Enable+ Count=32 Masked-
>>          Capabilities: [d0] Vital Product Data
>>          Capabilities: [100] Advanced Error Reporting
>>          Capabilities: [148] Virtual Channel
>>          Capabilities: [170] Device Serial Number 01-00-00-00-68-4c-e0-00
>>          Capabilities: [180] Secondary PCI Express
>>          Capabilities: [190] Transaction Processing Hints
>>          Capabilities: [21c] Latency Tolerance Reporting
>>          Capabilities: [224] L1 PM Substates
>>          Capabilities: [234] Vendor Specific Information: ID=0002 Rev=4 Len=100 <?>
>>          Kernel driver in use: r8169
>>          Kernel modules: r8169
>> - ethtool shows that the NIC claims to support and advertise
>>    2500baseT/Full while the Link partner advertises it too.
>>
>> Do these cards need more handling in the driver?  Can anyone report the
>> RTL8126_2 as working for them at all supported speeds (at least 1G and
>> above)?  Is there anything else I can get developers from these NICs?
>>
>> Sadly, I am out of ideas.  I am currently within the 30-day return so
>> have to consider that.  Otherwise, I do like them.