Still problem with "cb transfer status 1, cancelling" -> segmentation fault, libusb

Peter A. Bigot pab at
Tue Feb 12 21:33:31 UTC 2013

On 02/12/2013 01:34 PM, Markus Gonser wrote:
> Hello,
> I am new to this mailing list, but that does not mean that I have been 
> following SDR activities here at osmocom and especially gnuradio 
> actively. I am not a linux professional, but "intermediate beginner". 
> I currently have a problem running my Hama Nano DVB-T Dongle which I 
> cannot solve and therefore need to turn to you with the following problem:
> I hava an Intel Pentium 977 machine running Ubuntu 12.04LTS in the 
> 64bit version. I compiled and installed gnuradio using the script from 
> Marcus Leech (
> I have an Hama Nano DVB-T Dongle which contains an RTL2832U Chip 
> combined with the E4000 frontend.
> When I try to access the Dongle via rtlsdr (either via sample programs 
> in GRC or simply via rtl_test -s) I get
> cb transfer status: 1, canceling...
> Library error 0, exiting...
> Speicherzugriffsfehler (Speicherabzug geschrieben) (engl.: 
> "segmentation fault")
> I found two threads regarding this problem in this mailinglist:
> 1)
> 2)
> With respect to the former (1) I checked my version of 
> libusb-1.0-0-dev which is 2:1.0.9~rc3-2ubuntu1
> With respect to the latter (2) (and older post) I checked in my source 
> of the rtlsdr library if the proposed change is included and it is.
> So I do not have any clue how and where to proceed further. I'd be 
> happy to give you any more information you need and try out patches. 
> If you have any ideas or could point me to the right direction, I'd be 
> very happy about
> Thanks upfront for your consideration and best regards,
> Markus
> P.S.: The dongle worked on this machine before, but I do not remember 
> if I had the 32bit Ubuntu version running and which versions of 
> gnuradio, etc. were installed.
My conclusion from thread (1), based on the response from Peter Stuge, 
was that rtl-sdr was mis-using libusb by closing the device without 
waiting for it to finish, and it's not a fault in libusb. Looks like 
git:// is down, and the cgit browser is out of 
date, so I can't tell what's been done since.  But the fix needs to be 
made in rtl-sdr, whether it's reverting the patch as I suggested or 
correcting it to wait before shutting things down.

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