Re: [Discuss-gnuradio] Flowgraph stop execution when changing sample rate of uhd_single_usrp_source

[Tom Rondeau]

On Sun, Dec 5, 2010 at 12:22 PM, Josh Blum <address@hidden> wrote:
>
>
> On 12/05/2010 08:17 AM, Alexandru Csete wrote:
>> Greetings,
>>
>> Yesterday I updated my gnuradio/next and UHD installations to:
>> UHD_0001.20101204162446.a51fb2e
>> v3.3.1git-322-ge92f2cb6
>>
>> I noticed that when changing USRP sample rates using
>> uhd_single_usrp_source the flowgraph will suspend execution and CPU
>> load drops to 0.
>> The flowgraph is still alive in the sense that it is responsive to UI
>> commands and sometimes even resumes execution for 5-10 seconds then
>> stops again. No error message appears in the terminal.
>>
>> The previous versions I have installed don't have this problem:
>> UHD_0001.20101124180824.2568efd
>> v3.3.1git-227-gb245c628
>>
>> I also tried the combination UHD_0001.20101124180824.2568efd +
>> v3.3.1git-322-ge92f2cb6 and it also has this problem which lead me to
>> suspect gr-uhd rather than uhd.
>>
>
> There was a change to the uhd single usrp source to support the tags. It
> might be getting into a condition that gets stuck in the work function.
>
> size_t total_samps = 0;
>        while(total_samps + 362 < (size_t)noutput_items) {
>          size_t num_samps = _dev->get_device()->recv(
>              output_items, noutput_items, metadata,
>              //_type, uhd::device::RECV_MODE_FULL_BUFF
>              _type, uhd::device::RECV_MODE_ONE_PACKET
>          );
>
> This code looks really wrong. It will loop and the output_items pointer
> doesnt increase. There is also some magic constant in there. Tom?
>
> -Josh


Yeah, there is something wrong there. We threw this together WAY too
quickly the other week. I'll look into this tomorrow. My N210 isn't
responding to network updates of the new images and I can't spend any
more time on this tonight.

Tom