Sample rate check in Linux

uhd_cpp/uhd_spectrum/uhd_device.cpp

@@ -226,7 +226,7 @@ quint64 uhd_device::set_center_freq(const quint64 freq_in_hz)
 	{
 		double rate = usrp->get_rx_rate(m_channel);
 		using uhd::tune_request_t;
-		tune_request_t tune_request_rx = tune_request_t((double)freq_in_hz,rate/2);
+		tune_request_t tune_request_rx = tune_request_t((double)freq_in_hz/*,rate/2*/);
 		usrp->set_rx_freq(tune_request_rx,m_channel);
 		return (quint64)(usrp->get_rx_freq(m_channel));
 	}
@@ -258,11 +258,17 @@ double uhd_device::set_rx_gain(double gain)
 
 double uhd_device::set_rx_bandwidth(double bw)
 {
-	if (usrp)
+	if (usrp && bw>=200000)
 	{
 		usrp->set_rx_bandwidth(bw,m_channel);
 		bw = usrp->get_rx_bandwidth(m_channel);
 	}
+	else if (usrp )
+	{
+		usrp->set_rx_bandwidth(usrp->get_rx_rate(m_channel),m_channel);
+		bw = usrp->get_rx_bandwidth(m_channel);
+	}
+
 	return bw;
 
 }