rfnoc: Add halt to replay API

The HALT feature allows a command that takes a long time to run to be
stopped while it is in progress.

3 files changed, 12 insertions, 1 deletions

diff --git a/host/examples/replay_samples_from_file.cpp b/host/examples/replay_samples_from_file.cpp
index f9ef3cd45..a8b5d40e9 100644
--- a/host/examples/replay_samples_from_file.cpp
+++ b/host/examples/replay_samples_from_file.cpp
@@ -346,9 +346,13 @@ int UHD_SAFE_MAIN(int argc, char *argv[])
     cout << endl << "Stopping replay..." << endl;
     replay_ctrl->issue_stream_cmd(stream_cmd, replay_chan);
 
+    // The stop takes effect after the current command has completed, so use
+    // halt to stop the command in progress and clear any queued commands.
+    replay_ctrl->play_halt(replay_chan);
+
 
     ///////////////////////////////////////////////////////////////////////////
-    // Wait for the replay data to flush out
+    // Wait for any buffered replay data to finish playing out
 
     uint16_t prev_packet_count, packet_count;
 
diff --git a/host/include/uhd/rfnoc/replay_block_ctrl.hpp b/host/include/uhd/rfnoc/replay_block_ctrl.hpp
index bd5c47739..ba49a6a7d 100644
--- a/host/include/uhd/rfnoc/replay_block_ctrl.hpp
+++ b/host/include/uhd/rfnoc/replay_block_ctrl.hpp
@@ -60,6 +60,9 @@ public:
     //! Returns the size of the packets played by the Replay block (in 64-bit words)
     virtual uint32_t get_words_per_packet(const size_t chan) = 0;
 
+    //! Halts playback and clears the playback command FIFO
+    virtual void play_halt(const size_t chan) = 0;
+    
 }; /* class replay_block_ctrl*/
 
 }} /* namespace uhd::rfnoc */
diff --git a/host/lib/rfnoc/replay_block_ctrl_impl.cpp b/host/lib/rfnoc/replay_block_ctrl_impl.cpp
index 3809cebc0..e9b119085 100644
--- a/host/lib/rfnoc/replay_block_ctrl_impl.cpp
+++ b/host/lib/rfnoc/replay_block_ctrl_impl.cpp
@@ -98,6 +98,10 @@ public:
     uint32_t get_words_per_packet(const size_t chan) {
         return _params[chan].words_per_packet;
     }
+
+    void play_halt(const size_t chan) {
+        sr_write("RX_CTRL_HALT", 1, chan);
+    }
     
     
    /***************************************************************************