LE 9.2.0 generic, r8169 NIC connected at 1Gbps but real speed only 100Mbps

csh · February 24, 2020 at 7:32 PM

New hardware, Asrock J4105-ITX - Intel gemini lake SOC

NIC reports Gb speed but all transfers are only at 100Mbps.

ifconfig shows no dropped frames, everything looks ok.

Around 10m CAT5e cable, worked fine with previous HTPC.

Tried another router, doesn't help.

According to some google results blacklisting r8169 module could help but as it seems LE has it built into the kernel

Any ideas?

excerpt from dmesg:

Code

[    2.537772] libphy: r8169: probed
[    2.538032] r8169 0000:02:00.0 eth0: RTL8168h/8111h, 70:85:c2:fa:31:f4, XID 541, IRQ 124
[    2.538036] r8169 0000:02:00.0 eth0: jumbo features [frames: 9200 bytes, tx checksumming: ko]
[   12.840729] Generic Realtek PHY r8169-200:00: attached PHY driver [Generic Realtek PHY] (mii_bus:phy_addr=r8169-200:00, irq=IGNORE)
[   12.949712] r8169 0000:02:00.0 eth0: Link is Down
[   28.740218] r8169 0000:02:00.0 eth0: Link is Up - 1Gbps/Full - flow control rx/tx
[   28.740238] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready

Full dmesg: http://ix.io/2cAr

lshw:

Code

02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
Subsystem: ASRock Incorporation RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (Motherboard (one of many))
Flags: bus master, fast devsel, latency 0, IRQ 20
I/O ports at e000 [size=256]
Memory at a1104000 (64-bit, non-prefetchable) [size=4K]
Memory at a1100000 (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, MSI 01
Capabilities: [b0] MSI-X: Enable+ Count=4 Masked-
Capabilities: [100] Advanced Error Reporting
Capabilities: [140] Virtual Channel
Capabilities: [160] Device Serial Number f4-31-fa-c2-85-70-00-00
Capabilities: [170] Latency Tolerance Reporting
Capabilities: [178] L1 PM Substates
Kernel driver in use: r8169

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ifconfig:

Code

LibreELEC:~ # ifconfig
eth0      Link encap:Ethernet  HWaddr 70:85:C2:FA:31:F4
inet addr:192.168.1.101  Bcast:192.168.1.255  Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
RX packets:1183886 errors:0 dropped:3 overruns:0 frame:0
TX packets:595133 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1770511686 (1.6 GiB)  TX bytes:41212717 (39.3 MiB)

iperf:

Code

Connecting to host 192.168.1.101, port 5201
[  4] local 192.168.1.100 port 38310 connected to 192.168.1.101 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  11.8 MBytes  98.6 Mbits/sec    0   91.9 KBytes
[  4]   1.00-2.00   sec  11.2 MBytes  94.4 Mbits/sec    0   91.9 KBytes
[  4]   2.00-3.00   sec  11.2 MBytes  94.3 Mbits/sec    0   99.0 KBytes
[  4]   3.00-4.00   sec  11.2 MBytes  94.4 Mbits/sec    0   99.0 KBytes
[  4]   4.00-5.00   sec  11.2 MBytes  93.8 Mbits/sec    0   99.0 KBytes
[  4]   5.00-6.00   sec  11.2 MBytes  94.3 Mbits/sec    0   99.0 KBytes
[  4]   6.00-7.00   sec  11.2 MBytes  94.3 Mbits/sec    0   99.0 KBytes
[  4]   7.00-8.00   sec  11.2 MBytes  93.8 Mbits/sec    0   99.0 KBytes
[  4]   8.00-9.00   sec  11.2 MBytes  94.4 Mbits/sec    0   99.0 KBytes
[  4]   9.00-10.00  sec  11.2 MBytes  93.8 Mbits/sec    0   99.0 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec   113 MBytes  94.6 Mbits/sec    0             sender
[  4]   0.00-10.00  sec   112 MBytes  94.2 Mbits/sec                  receiver

iperf Done.

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**Da Flex** · February 24, 2020 at 8:28 PM Official Post

Try this blacklist method.

csh · February 25, 2020 at 5:20 AM

I could, but does LE have another driver for this NIC?

Other linux distributions (ubuntu) can compile proprietary r8168 from repository that should work with some hardware.

I don't know if this is available in LE.

Last night NIC suddenly started working full speed. This morning again gets only to 100Mbps

**chewitt** · February 25, 2020 at 9:46 AM Official Post

LE has the r8168 driver included for years. Issues with r8169 being detected and users seeing performance issues have also been occurring for many years (since OpenELEC days). Go test the blacklisting.

csh · February 25, 2020 at 7:21 PM

Included as module?

Didn't find it in /lib

Took me a while to find the correct initcall string to append, here it is for reference: initcall_blacklist=rtl8169_pci_driver_init

No network after blacklisting the r8169 driver

**smp** · February 25, 2020 at 7:55 PM

I have the same motherboard with the same Realtek chip. No issues here:

Code

Connecting to host 192.168.88.199, port 5201
[  5] local 192.168.88.7 port 43690 connected to 192.168.88.199 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   114 MBytes   954 Mbits/sec    0    404 KBytes
[  5]   1.00-2.00   sec   113 MBytes   945 Mbits/sec    0    424 KBytes
[  5]   2.00-3.00   sec   113 MBytes   945 Mbits/sec    0    540 KBytes
[  5]   3.00-4.00   sec   111 MBytes   935 Mbits/sec   14    460 KBytes
[  5]   4.00-5.00   sec   112 MBytes   941 Mbits/sec    0    509 KBytes
[  5]   5.00-6.00   sec   112 MBytes   941 Mbits/sec    0    530 KBytes
[  5]   6.00-7.00   sec   112 MBytes   942 Mbits/sec    0    570 KBytes
[  5]   7.00-8.00   sec   112 MBytes   941 Mbits/sec    0    594 KBytes
[  5]   8.00-9.00   sec   112 MBytes   940 Mbits/sec    0    595 KBytes
[  5]   9.00-10.00  sec   113 MBytes   944 Mbits/sec    0    602 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  1.10 GBytes   943 Mbits/sec   14             sender
[  5]   0.00-10.00  sec  1.10 GBytes   941 Mbits/sec                  receiver

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Try to test with another cable. At Gigabit speed Realtek NICs are very picky with ethernet cables. I've seen some short cat5e cables that work fine at 100M but fail at 1000M.

I'm using Cat6 7.5m cable.

csh · February 25, 2020 at 9:17 PM

Thx, I'll try another cable.

Wouldn't in case of bad cable NIC connect at 100Mbps or show some errors/dropped frames?

Old MBO had similar realtek, was using the same r8169 driver under LE 8.2.5 and was running fine for years. Too bad that j4105 doesn't work with older LE.

Perhaps it's time to pull the cable out of the wall and replace it

**smp** · February 25, 2020 at 9:29 PM

Quote from csh

Wouldn't in case of bad cable NIC connect at 100Mbps or show some errors/dropped frames?

In your case it looks like it does connect at 100M but for some reason reports 1000M.

I would test it with a short, known good cable before pulling out any cables from the wall

csh · February 29, 2020 at 12:38 PM

Solved

One of the connectors had a little oxidized contacts.

It seems realtek driver does not report correctly speed, bad/ dropped frames or anything.

LE even boots faster, before systemd log was showing 15s wait for network service, now only 3s.