Re: rge(4) RTL8126 simple testing

[Sean C. Farley]

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
--
s...@freebsd.org


On Wed, 4 Mar 2026 at 13:02, Sean C. Farley <s...@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.