Re: [Discuss-gnuradio] USRP2 with Realtek r8169 Problem

[Soeren Peik]

On 07/16/2010 08:30 AM, Soeren Peik wrote:
> Hi all,
>
> I just received my USRP2 and hooked it up to a three month old 
> Thinkpad Edge 13 intel with Realtek ethernet Chipset.
>
> System is: Ubuntu 10.04 LTS Lucid Lynx
> Firmware: txrx_wbx_raw_eth_20100608.bin
> FPGA-FW: u2_rev3-20100603.bin
> Daughterboard: WBX
>
> When i run the fft application with  with sudo usrp2_fft.py -f98e6
> I  get overruns "SSSSSSS" and the GUI hangs.
>
> Changing the decimation does not help.
> The USRP2 is operating as I can clearly see the local FM-Stations in 
> the spectrum.
>
> Older Threads suggested problems with inserted pauses. When checking 
> with ethtool I get:
>
> Settings for eth0:
>     Supported ports: [ TP MII ]
>     Supported link modes:   10baseT/Half 10baseT/Full
>                             100baseT/Half 100baseT/Full
>                             1000baseT/Half 1000baseT/Full
>     Supports auto-negotiation: Yes
>     Advertised link modes:  10baseT/Half 10baseT/Full
>                             100baseT/Half 100baseT/Full
>                             1000baseT/Half 1000baseT/Full
>     Advertised pause frame use: No
>     Advertised auto-negotiation: Yes
>     Link partner advertised link modes:  1000baseT/Half 1000baseT/Full
>     Link partner advertised pause frame use: No
>     Link partner advertised auto-negotiation: Yes
>     Speed: 1000Mb/s
>     Duplex: Full
>     Port: MII
>     PHYAD: 0
>     Transceiver: internal
>     Auto-negotiation: on
>     Supports Wake-on: pumbg
>     Wake-on: g
>     Current message level: 0x00000033 (51)
>     Link detected: yes
>
> And with nm-tools I get
>
>
> - Device: eth0  [USRP Link] 
> ----------------------------------------------------
>   Type:              Wired
>   Driver:            r8169
>   State:             connected
>   Default:           no
>   HW Address:        C8:0A:A9:25:64:5E
>
>   Capabilities:
>     Carrier Detect:  yes
>     Speed:           1000 Mb/s
>
>   Wired Properties
>     Carrier:         on
>
>   IPv4 Settings:
>     Address:         192.168.10.1
>     Prefix:          24 (255.255.255.0)
>     Gateway:         0.0.0.0
>
> This looks OK to be.
>
>
> I do not get problems when transmitting.
>
> Do you any suggestion for a fix?
> Unfortunately, I do not have another computer here to try out other 
> setups.
>
>
> Thanks in advance,
> Soeren
>
>
>
>
>
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I did some more research and kind of fixed the problem. The problem is 
twofold. The Realtek driver is bad, as mentioned often here in the
list. Try to avoid it when you can. I am stuck with it and get very bad 
performance. However it works with lower data rates, e.g. decimation of 
50 or more. Do not run any other programs in parallel. Even by moving 
the mouse I get dropped packages.

The issue of the hanging fft-graph can be fixed by reducing the fft-size 
to 512 or 256. Then the gui remains responsive.

Soeren