usrp: fix rate calculation logic

4 files changed, 17 insertions, 8 deletions

diff --git a/host/lib/usrp/cores/rx_dsp_core_200.cpp b/host/lib/usrp/cores/rx_dsp_core_200.cpp
index 6d306d507..b97f9c58e 100644
--- a/host/lib/usrp/cores/rx_dsp_core_200.cpp
+++ b/host/lib/usrp/cores/rx_dsp_core_200.cpp
@@ -149,8 +149,7 @@ public:
     }
 
     double set_host_rate(const double rate){
-        const size_t decim_rate = this->get_host_rates().clip(
-            boost::math::iround(_tick_rate/rate), true);
+        const size_t decim_rate = boost::math::iround(_tick_rate/this->get_host_rates().clip(rate, true));
         size_t decim = decim_rate;
 
         //determine which half-band filters are activated
diff --git a/host/lib/usrp/cores/tx_dsp_core_200.cpp b/host/lib/usrp/cores/tx_dsp_core_200.cpp
index 1d571ea7c..9d90d30cc 100644
--- a/host/lib/usrp/cores/tx_dsp_core_200.cpp
+++ b/host/lib/usrp/cores/tx_dsp_core_200.cpp
@@ -89,8 +89,7 @@ public:
     }
 
     double set_host_rate(const double rate){
-        const size_t interp_rate = this->get_host_rates().clip(
-            boost::math::iround(_tick_rate/rate), true);
+        const size_t interp_rate = boost::math::iround(_tick_rate/this->get_host_rates().clip(rate, true));
         size_t interp = interp_rate;
 
         //determine which half-band filters are activated
diff --git a/host/lib/usrp/usrp1/io_impl.cpp b/host/lib/usrp/usrp1/io_impl.cpp
index 31c834109..937706fdd 100644
--- a/host/lib/usrp/usrp1/io_impl.cpp
+++ b/host/lib/usrp/usrp1/io_impl.cpp
@@ -470,8 +470,7 @@ uhd::meta_range_t usrp1_impl::get_tx_dsp_host_rates(void){
 double usrp1_impl::update_rx_samp_rate(size_t dspno, const double samp_rate){
 
     const size_t div = this->has_rx_halfband()? 2 : 1;
-    const size_t rate = this->get_rx_dsp_host_rates().clip(
-        boost::math::iround(_master_clock_rate / samp_rate), true);
+    const size_t rate = boost::math::iround(_master_clock_rate/this->get_rx_dsp_host_rates().clip(samp_rate, true));
 
     if (rate < 8 and this->has_rx_halfband()) UHD_MSG(warning) <<
         "USRP1 cannot achieve decimations below 8 when the half-band filter is present.\n"
@@ -499,8 +498,7 @@ double usrp1_impl::update_rx_samp_rate(size_t dspno, const double samp_rate){
 double usrp1_impl::update_tx_samp_rate(size_t dspno, const double samp_rate){
 
     const size_t div = this->has_tx_halfband()? 2 : 1;
-    const size_t rate = this->get_tx_dsp_host_rates().clip(
-        boost::math::iround(_master_clock_rate / samp_rate), true);
+    const size_t rate = boost::math::iround(_master_clock_rate/this->get_tx_dsp_host_rates().clip(samp_rate, true));
 
     if (dspno == 0){ //only care if dsp0 is set since its homogeneous
         bool s = this->disable_tx();
diff --git a/host/tests/ranges_test.cpp b/host/tests/ranges_test.cpp
index 5f6de4645..85bb4c3c4 100644
--- a/host/tests/ranges_test.cpp
+++ b/host/tests/ranges_test.cpp
@@ -55,3 +55,16 @@ BOOST_AUTO_TEST_CASE(test_ranges_clip){
     BOOST_CHECK_CLOSE(mr.clip(50.9, false), 50.9, tolerance);
     BOOST_CHECK_CLOSE(mr.clip(50.9, true), 51.0, tolerance);
 }
+
+BOOST_AUTO_TEST_CASE(test_ranges_clip2){
+    meta_range_t mr;
+    mr.push_back(range_t(1.));
+    mr.push_back(range_t(2.));
+    mr.push_back(range_t(3.));
+
+    BOOST_CHECK_CLOSE(mr.clip(2., true), 2., tolerance);
+    BOOST_CHECK_CLOSE(mr.clip(0., true), 1., tolerance);
+    BOOST_CHECK_CLOSE(mr.clip(1.2, true), 1., tolerance);
+    BOOST_CHECK_CLOSE(mr.clip(3.1, true), 3., tolerance);
+    BOOST_CHECK_CLOSE(mr.clip(4., true), 3., tolerance);
+}