# Connect 2 laptops by firewire-net [SOLVED]

## widlokm

Hello,

I'm trying to connect 2 lenovo T400 laptops using firewire (ieee1394) port. Kernel seems to properly detect chipset, however it is not possible to send anything over firewire0. Log messages are:

```
[    0.600134] firewire_ohci 0000:15:00.1: added OHCI v1.10 device as card 0, 4 IR + 4 IT contexts, quirks 0x11

[    0.600248] firewire_ohci 0000:15:00.1: isochronous cycle inconsistent

[    1.100307] firewire_core 0000:15:00.1: created device fw0: GUID 00061b032a42d831, S400

[   31.180542] firewire_core 0000:15:00.1: giving up on node ffc1: reading config rom failed: no ack

[   31.180552] firewire_core 0000:15:00.1: phy config: new root=ffc0, gap_count=5

[   69.992965] net firewire0: IP over IEEE 1394 on card 0000:15:00.1

[   69.993002] firewire_core 0000:15:00.1: refreshed device fw0

```

On other machine I get:

```
firewire_core: giving up on node ffc1: reading rom failed: timeout

```

The chipset:

```
FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller (rev 04)

```

 After enabling debug for firewire_ohci module it floods the log with messages:

```
[ 2251.845655] firewire_ohci 0000:15:00.1: AT spd 2 tl 24, ffc0 -> ffc1, pending/cancelled, QR req, fffff0000480

[ 2251.845711] firewire_ohci 0000:15:00.1: AR spd 2 tl 25, ffc1 -> ffc0, ack_complete, QR resp = 00000000

[ 2251.845723] firewire_ohci 0000:15:00.1: AT spd 2 tl 25, ffc0 -> ffc1, pending/cancelled, QR req, fffff0000484

[ 2251.845771] firewire_ohci 0000:15:00.1: AT spd 2 tl 26, ffc0 -> ffc1, evt_missing_ack, QR req, fffff0000488

[ 2251.845793] firewire_core 0000:15:00.1: giving up on node ffc1: reading config rom failed: no ack

[ 2251.845843] firewire_ohci 0000:15:00.1: AR spd 0 tl 27, ffc1 -> ffc0, ack_complete, Lk resp 4,2

[ 2251.845852] firewire_ohci 0000:15:00.1: AT spd 0 tl 27, ffc0 -> ffc1, pending/cancelled, Lk req, fffff000021c 8,2

```

While firewire0 interface can be set by ifconfig without errors, it is not possible to transmit anything over it - byte counters are always 0. I've tried loading firewire modules with cable disconnected, connected, etc. - still the same problem. Kernel is 4.4.26 from gentoo distribution, however I've compiled one myself. Do You know what can be wrong? Is it possible that faulty cable is creating such errors (electrical connections on cable seems to be OK, checked with ohmmeter)? 

Thank You in advance,

Michael WidlokLast edited by widlokm on Tue Feb 21, 2017 6:55 am; edited 1 time in total

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## widlokm

Hi,

It turns out that the problem was a bad firewire cable. I double check non-working one and electrical connections are OK, so it have to be wrong screen/capacity/impedance or something like this. With different one (better?) laptops connected OK and communication is solid.

Best Regards,

Michael Widlok

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