[SOLVED] Manually Assign Kernel Driver to Single NIC

HCF · 2022-02-26 07:13:24

I have two NICs, one of which is a RTL8125 2.5GbE Controller. It was unable to negotiate the advertised link speed out-of-the-box, which is why I've installed the r8125-dkms package. My hope is/was that this would fix the link speed.

lspci -l yields the following, indicating the NIC is not using the correct driver. If I was to blacklist the r8169 kernel driver to force the use of r8125, the second NIC would get disabled, which I do not want to do.

01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller (rev 05)
	Subsystem: ASRock Incorporation Device 8125
	Kernel driver in use: r8169
	Kernel modules: r8169, r8125
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0e)
	Subsystem: ASRock Incorporation Motherboard (one of many)
	Kernel driver in use: r8169
	Kernel modules: r8169

How do I manually assign a kernel driver to a single NIC (r8125), or selectively blacklist a specific kernel driver for a single NIC (r8169)?

Any help would be appreciated

Last edited by HCF (2022-03-09 01:02:14)

seth · 2022-02-26 08:12:27

https://wiki.archlinux.org/title/Modali … _come_from?
https://web.archive.org/web/20200112010 … dware.html

Aliasing the relevant pci entry (vendor/model/glob, see "lspci -nn") "off" might help, https://wiki.archlinux.org/title/Kernel_module#Aliasing

But in you case you'll likely get away w/ loading r8125 ahead (eg. move it to the initramfs or blacklist the r8169 module and only load it explicitly afterwards)

HCF · 2022-02-26 08:44:04

Moving it to the initramfs did the trick, thank you!

Still not negotiating at the right link speed (10000baseT/Full vs 2500baseT/Full), but at least the correct kernel driver is now loaded.

Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Full
	                        2500baseT/Full
	Supported pause frame use: Symmetric Receive-only
	Supports auto-negotiation: Yes
	Supported FEC modes: Not reported
	Advertised link modes:  10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Full
	                        2500baseT/Full
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Advertised FEC modes: Not reported
	Link partner advertised link modes:  1000baseT/Full
	                                     10000baseT/Full
	                                     2500baseT/Full
	                                     5000baseT/Full
	Link partner advertised pause frame use: No
	Link partner advertised auto-negotiation: Yes
	Link partner advertised FEC modes: Not reported
	Speed: 1000Mb/s
	Duplex: Full
	Auto-negotiation: on
	Port: Twisted Pair
	PHYAD: 0
	Transceiver: internal
	MDI-X: Unknown
	Supports Wake-on: pumbg
	Wake-on: g
        Current message level: 0x00000033 (51)
                               drv probe ifdown ifup
	Link detected: yes

At the risk of pivoting somewhat off-topic, would you happen to know why this would be the case? I read through https://bbs.archlinux.org/viewtopic.php?id=262075, however running that command completely freezes my system.

seth · 2022-02-26 08:55:54

running that command completely freezes my system

On the r8125 or r8169 module or both?
Because of the autonegotiation not getting up to 2500, is this a cat7 or higher cable?
(cat6 is insufficient and cat6a is an unreliable ISO/IEC vs. EIA/TIA mess; so maybe works - maybe not)

HCF · 2022-02-26 09:44:57

The same cable previously worked great at 10000Mb/s (CPU died so had to migrate my Arch install over to another box), so that's definitely not it.

This time I managed to see the result--the system froze soon after.

	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Full
	                        2500baseT/Full
	Supported pause frame use: Symmetric Receive-only
	Supports auto-negotiation: Yes
	Supported FEC modes: Not reported
	Advertised link modes:  2500baseT/Full
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Advertised FEC modes: Not reported
	Speed: Unknown!
	Duplex: Unknown! (255)
	Auto-negotiation: on
	Port: Twisted Pair
	PHYAD: 0
	Transceiver: internal
	MDI-X: Unknown
	Supports Wake-on: pumbg
	Wake-on: g
        Current message level: 0x00000033 (51)
                               drv probe ifdown ifup
	Link detected: no

Last edited by HCF (2022-02-26 09:45:29)

seth · 2022-02-26 15:50:26

Link detected: no

The carrier breaks away.
Is this on the r8125-dkms or r8169 module?
"network-interface-controllers-10-100-1000m-gigabit-ethernet-pci-express-software" sounds like there's no 2.5Gbps support and according to https://github.com/TallGuy74/r8125 there're some options (check modinfo) that allow to set the speed… up to 1000Mbps
Did you ever try enforcing the speed on the r8169 module?

HCF · 2022-02-26 20:51:57

Same result for both r8125 and r8169.

The GitHub readme doesn't sound too promising, seems like 2500m is indeed not supported for now. That's what I get for once not sticking to Intel NICs

Thanks for your help!

Last edited by HCF (2022-02-26 20:52:20)

hkall · 2022-02-27 10:55:23

RTL8125 works with r8169 at 2.5Gbps for me (with a GS110MX Multi-Gig switch). Check your dmesg log, there should be a downshift info. Most likely the issue is on the physical side.

HCF · 2022-02-27 20:29:04

I did some further reading and it sounds like multi-gig requires a switch for link speed negotiation (thanks for pointing me in the right direction hkall). As I am running a point-to-point connection into an Intel X550, multi-gig does not seem to be supported.

hkall · 2022-02-27 22:27:10

Also back to back connectivity should work as long as both link partners support auto-negotiation. Some people reported that the X550 driver doesn't advertise NBase-T modes per default, and e.g. 2.5Gbps has to be activated manually.
-> https://forums.unraid.net/bug-reports/p … ink-r1587/
However your ethtool output shows that the link partner advertises 2.5Gbps, so this may not be the root cause here.

HCF · 2022-02-28 05:32:42

I took this as an excuse to finally buy a 10G switch (MikroTik CRS305-1G-4S+IN); will update this thread once it arrives. Fingers crossed!

seth · 2022-02-28 18:18:55

Possible pattern: https://bbs.archlinux.org/viewtopic.php?id=274539

HCF · 2022-03-01 04:51:05

To clarify, the network itself is working perfectly fine, just not at the link speed I would like.

HCF · 2022-03-09 01:03:44

Confirming that using a switch fixed the link speed, everything is now working as expected. The r8125 kernel driver was not needed.

Arch Linux

#1 2022-02-26 07:13:24

[SOLVED] Manually Assign Kernel Driver to Single NIC

#2 2022-02-26 08:12:27

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#3 2022-02-26 08:44:04

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#4 2022-02-26 08:55:54

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#5 2022-02-26 09:44:57

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#6 2022-02-26 15:50:26

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#7 2022-02-26 20:51:57

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#8 2022-02-27 10:55:23

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#9 2022-02-27 20:29:04

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#10 2022-02-27 22:27:10

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#11 2022-02-28 05:32:42

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#12 2022-02-28 18:18:55

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#13 2022-03-01 04:51:05

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

#14 2022-03-09 01:03:44

Re: [SOLVED] Manually Assign Kernel Driver to Single NIC

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