mg: Update gain immediately after setting frequency

We want to have set frequency and set gain atomic. i.e if user set gain and
tune to different frequency, they expect the gain won't change.

Reviewed-By: Martin Braun <martin.braun@ettus.com>

2 files changed, 37 insertions, 5 deletions

diff --git a/host/lib/usrp/dboard/magnesium/magnesium_radio_ctrl_impl.cpp b/host/lib/usrp/dboard/magnesium/magnesium_radio_ctrl_impl.cpp
index ae7f68710..090281d82 100644
--- a/host/lib/usrp/dboard/magnesium/magnesium_radio_ctrl_impl.cpp
+++ b/host/lib/usrp/dboard/magnesium/magnesium_radio_ctrl_impl.cpp
@@ -97,14 +97,24 @@ namespace {
     // TODO: remove this helper when there are only 2 radios
     fs_path master_fe_base_path(const std::string &radio_slot)
     {
-        if (radio_slot == "B") {
+        if (radio_slot == "B" or radio_slot == "A") {
             return fs_path("dboards") / "A";
         }
-        if (radio_slot == "D") {
+        if (radio_slot == "D" or radio_slot == "C") {
             return fs_path("dboards") / "C";
         }
         UHD_THROW_INVALID_CODE_PATH();
     }
+      fs_path slave_fe_base_path(const std::string &radio_slot)
+    {
+        if (radio_slot == "B" or radio_slot == "A") {
+            return fs_path("dboards") / "B";
+        }
+        if (radio_slot == "D" or radio_slot == "C") {
+            return fs_path("dboards") / "D";
+        }
+        UHD_THROW_INVALID_CODE_PATH();
+    }
 }
 
 
@@ -202,6 +212,7 @@ double magnesium_radio_ctrl_impl::set_tx_frequency(
             master_fe_base_path(_radio_slot) / fs_path("tx_frontends") / chan;
         UHD_LOG_DEBUG(unique_id(),
                       "Slave setting TX frequency");
+
         return _tree->access<double>(master_tx_fe_path / "freq" / "value")
             .set(freq)
             .get();
@@ -228,11 +239,29 @@ double magnesium_radio_ctrl_impl::set_tx_frequency(
     }
 
     //const double actual_ad9371_freq =
-        _ad9371->set_frequency(freq, chan, TX_DIRECTION);
-    radio_ctrl_impl::set_tx_frequency(freq, chan);
+    _ad9371->set_frequency(freq, chan, TX_DIRECTION);
+    this->_update_gain(chan, TX_DIRECTION);
     return freq; // FIXME calc the actual frequency
 }
 
+void magnesium_radio_ctrl_impl::_update_gain(
+        const size_t chan,
+        const uhd::direction_t dir
+) {
+    const std::string fe =
+        (dir == TX_DIRECTION) ? "tx_frontends" : "rx_frontends";
+    const fs_path slave_fe_path =
+            slave_fe_base_path(_radio_slot) / fs_path(fe) / chan;
+    const double freq =  (dir == TX_DIRECTION) ?
+        this->get_tx_frequency(chan) :
+        this->get_rx_frequency(chan);
+    // "this" here is always master
+    this->_set_all_gain(this->_get_all_gain(chan, dir), freq, chan, dir);
+    // now we need update gain on slave
+    _tree->access<double>(slave_fe_path / "gains" / "all" / "value").update();
+
+}
+
 double magnesium_radio_ctrl_impl::set_rx_frequency(
         const double freq,
         const size_t chan
@@ -252,7 +281,7 @@ double magnesium_radio_ctrl_impl::set_rx_frequency(
             .set(freq)
             .get();
     }
-    // If we're on the slave, we use the master lock or we get a deadlock
+    // If we're on the slave, we use the master lock or we'd get a deadlock
     std::lock_guard<std::mutex> l(_set_lock);
     // We need to set the switches on both channels, because they share an LO.
     // This way, if we tune channel 0 it will not put channel 1 into a bad
@@ -276,6 +305,7 @@ double magnesium_radio_ctrl_impl::set_rx_frequency(
     //const double actual_ad9371_freq =
     _ad9371->set_frequency(freq, chan, RX_DIRECTION);
     radio_ctrl_impl::set_rx_frequency(freq, chan);
+    this->_update_gain(chan, RX_DIRECTION);
     return freq; // FIXME calc the actual frequency
 }
 
diff --git a/host/lib/usrp/dboard/magnesium/magnesium_radio_ctrl_impl.hpp b/host/lib/usrp/dboard/magnesium/magnesium_radio_ctrl_impl.hpp
index ce96eb200..c4c07cf97 100644
--- a/host/lib/usrp/dboard/magnesium/magnesium_radio_ctrl_impl.hpp
+++ b/host/lib/usrp/dboard/magnesium/magnesium_radio_ctrl_impl.hpp
@@ -169,6 +169,8 @@ private:
         const direction_t dir
     );
 
+    void _update_gain(const size_t chan, direction_t dir);
+
     /**************************************************************************
      * CPLD Controls (implemented in magnesium_radio_ctrl_cpld.cpp)
      *************************************************************************/