setGain no working with bladeRF 2.0

[pothosware]

setGain no working with bladeRF 2.0

[guruofquality]

The implementation is transparently calling bladerf_get_gain and bladerf_set_gain:

• https://github.com/pothosware/SoapyBladeRF/blob/master/bladeRF_Settings.cpp#L361
• https://github.com/pothosware/SoapyBladeRF/blob/master/bladeRF_Settings.cpp#L381

So it might be a bug in libbladerf. You can put a few prints in there to confirm its libbladerf?

[drahosj]

The bladeRF, as of the release of the bladeRFmicro, does support AGC. I wonder if calls to bladerf_set_gain are just silently ignored if gain control is set to automatic? That would only be the case on RX channels.

…

On Thu, Feb 14, 2019 at 9:02 AM Josh Blum ***@***.***> wrote: The implementation is transparently calling bladerf_get_gain and bladerf_set_gain: - https://github.com/pothosware/SoapyBladeRF/blob/master/bladeRF_Settings.cpp#L361 - https://github.com/pothosware/SoapyBladeRF/blob/master/bladeRF_Settings.cpp#L381 So it might be a bug in libbladerf. You can put a few prints in there to confirm its libbladerf? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#30 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABRgP2lKpbP4gSZHtxUdGNBoZ8mz6IxUks5vNXqAgaJpZM4a7M39> .

[KarlL2]

Thanks @drahosj, it seems I first need to explicitly disable the gain, before I can set it.

I don't know if it's the expected/usual behavior.

There still seem to be other errors on the libbladerf part, see Nuand/bladeRF#731 .

[KarlL2]

I found what the real issue was, for the BladeRF2.

In BladeRF test_gain.c, there is

/* Enable channel (necessary for RX gain changes to register
* on bladerf2) */
status = bladerf_enable_module(dev, ch, true);

I've currently updated the SoapyBladeRF code to this

void bladeRF_SoapySDR::setGain(const int direction, const size_t channel, const double value)
{
    // Enable channel (necessary for RX gain changes to register on bladerf2)
    // See bladeRF/host/libraries/libbladeRF_test/test_ctrl/src/test_gain.c
    int ret = bladerf_enable_module(_dev, _toch(direction, channel), true);
    if (ret != 0)
    {
        SoapySDR::logf(SOAPY_SDR_ERROR, "bladerf_enable_module returned %s", _err2str(ret).c_str());
        throw std::runtime_error("setGain() " + _err2str(ret));
    }

    ret = bladerf_set_gain(_dev, _toch(direction, channel), bladerf_gain(std::round(value)));
    if (ret != 0)
    {
        SoapySDR::logf(SOAPY_SDR_ERROR, "bladerf_set_gain(%f) returned %s", value, _err2str(ret).c_str());
        throw std::runtime_error("setGain() " + _err2str(ret));
    }
}

I'm not sure if it's possible to know if the channel is already enabled to avoid redoing it, nor if it causes issues if it's already opened.

Also this might make more sense for the BladeRF code to take care of that...

[guruofquality]

It seems like we should be able to call bladerf_enable_module in the constructor then. Can you try removing it from setup/closeStream, and move them to the constructor instead?

[KarlL2]

It seems to be working (I haven't done extensive tests). I removed the bladerf_enable_module calls from setupStream and closeStream and created a simple function to enable or disable all channels in both directions, that I call in the constructor and destructor:

void bladeRF_SoapySDR::_enable_or_disable_module(const bool enable, const bool throwOnError) {
  std::vector<int> directions;
  directions.push_back(SOAPY_SDR_RX);
  directions.push_back(SOAPY_SDR_TX);

  std::vector<size_t> channels;
  channels.push_back(0);
  if (_isBladeRF2)
    channels.push_back(1);

  for (const auto dir : directions) {
    for (const auto ch : channels)
    {
      const int ret = bladerf_enable_module(_dev, _toch(dir, ch), enable);
      if (ret != 0)
      {
        SoapySDR::logf(SOAPY_SDR_ERROR, "bladerf_enable_module(%s) returned %s", enable ? "true" : "false", _err2str(ret).c_str());
        if (throwOnError)
          throw std::runtime_error("bladerf_enable_module() " + _err2str(ret));
      }
    }
  }

  directions.clear();
  channels.clear();
}