AssertionError: accum_timeout < _timeout in wait_for_ack

[YIN-hechen]

hello

I am having USRP b200mini device with following tool versions:

arch: arm64
os: ubuntu20.04(kernel 5.10.198)
uhd: v4.7.0.0
usb: 3.0

Execute the following code, run for some time will report an error

#include <uhd/usrp/multi_usrp.hpp>
#include <csignal>


static bool stop_signal_called = false;

#define SAMPS_SIZE  2e6

void sig_int_handler(int)
{
    stop_signal_called = true;
}


int main(int argc, char* argv[])
{
    uhd::usrp::multi_usrp::sptr usrp;
    uhd::rx_streamer::sptr rx_stream;
    size_t max_num_samps;
    std::vector<std::complex<float>> buff_ptrs(SAMPS_SIZE);
    std::vector<double> freqs = {3e8, 5e8, 7e8, 9e8, 1e9, 2e9, 3e9, 4e9, 5e9};
    int index = 0;
    uhd::rx_metadata_t md;
    
    usrp = uhd::usrp::multi_usrp::make("");
    usrp->set_time_now(uhd::time_spec_t(0.0));

    uhd::stream_args_t stream_args("fc32","sc16");
    rx_stream = usrp->get_rx_stream(stream_args);

    max_num_samps = rx_stream->get_max_num_samps();

    std::signal(SIGINT, &sig_int_handler);

    usrp->set_rx_bandwidth(56e6);
    usrp->set_rx_rate(56e6);
    usrp->set_rx_gain(40);


    while(not stop_signal_called)
    {
        if(index > freqs.size() - 1)
            index = 0;
        usrp->set_rx_freq(freqs[index]);
        printf("set_rx_freq=%f\n", freqs[index]);
        usrp->set_rx_antenna(index % 2 == 1 ? "TX/RX" : "RX2");
        index++;

        //usleep(200000);

        uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_START_CONTINUOUS);
        stream_cmd.stream_now = true;
        rx_stream->issue_stream_cmd(stream_cmd);

        size_t num_acc_samps = 0;
        size_t num_rx_samps;
        float *buff = (float *)&buff_ptrs[0];
        while(num_acc_samps < SAMPS_SIZE)
        {
            if((SAMPS_SIZE-num_acc_samps) > max_num_samps)
            {
                num_rx_samps = rx_stream->recv(buff+(num_acc_samps*2), max_num_samps, md, 3.0);
            }else
            {
                num_rx_samps = rx_stream->recv(buff+(num_acc_samps*2), SAMPS_SIZE-num_acc_samps, md, 3.0);    
            }

            if (md.error_code == uhd::rx_metadata_t::ERROR_CODE_TIMEOUT) {
                printf("error_code=%s\n",  md.strerror().data());
                break;
            }
            
            if (md.error_code == uhd::rx_metadata_t::ERROR_CODE_NONE) {
                num_acc_samps += num_rx_samps;
            }
        }

        rx_stream->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS);

        usleep(200000); 
    }

    return 0;
}

error message:
0000000000000000000000000set_rx_freg=900000000.000000
000000error_code=ERROR_CODE_TIMEOUT
terminate called after throwing an instance of 'uhd::assertion_error'
what(): AssertionError: accum_timeout < _timeout in wait_for_ack
at /home/xxx/uhd/uhd-4.7.0.0/host/lib/usrp/b200/b200 _radio_ctrl_core.cpp:227

Anybody a hint what to do?