calculate max samples per packet using otw type

4 files changed, 37 insertions, 19 deletions

diff --git a/host/lib/usrp/usrp2/io_impl.cpp b/host/lib/usrp/usrp2/io_impl.cpp
index 7c9d003ce..de0c76eb1 100644
--- a/host/lib/usrp/usrp2/io_impl.cpp
+++ b/host/lib/usrp/usrp2/io_impl.cpp
@@ -31,10 +31,16 @@ namespace asio = boost::asio;
  * Helper Functions
  **********************************************************************/
 void usrp2_impl::io_init(void){
-    //setup otw type
-    _otw_type.width = 16;
-    _otw_type.shift = 0;
-    _otw_type.byteorder = otw_type_t::BO_BIG_ENDIAN;
+    //setup rx otw type
+    _rx_otw_type.width = 16;
+    _rx_otw_type.shift = 0;
+    _rx_otw_type.byteorder = otw_type_t::BO_BIG_ENDIAN;
+
+    //setup tx otw type
+    _tx_otw_type.width = 16;
+    _tx_otw_type.shift = 0;
+    _tx_otw_type.byteorder = otw_type_t::BO_BIG_ENDIAN;
+
 
     //initially empty copy buffer
     _rx_copy_buff = asio::buffer("", 0);
@@ -49,7 +55,8 @@ void usrp2_impl::io_init(void){
     send_buff->done(sizeof(data));
 
     //setup RX DSP regs
-    _iface->poke32(FR_RX_CTRL_NSAMPS_PER_PKT, _max_rx_samples_per_packet);
+    std::cout << "RX samples per packet: " << max_rx_samps_per_packet() << std::endl;
+    _iface->poke32(FR_RX_CTRL_NSAMPS_PER_PKT, max_rx_samps_per_packet());
     _iface->poke32(FR_RX_CTRL_NCHANNELS, 1);
     _iface->poke32(FR_RX_CTRL_CLEAR_OVERRUN, 1); //reset
     _iface->poke32(FR_RX_CTRL_VRT_HEADER, 0
@@ -121,7 +128,7 @@ size_t usrp2_impl::send(
     boost::uint32_t *tx_mem = send_buff->cast<boost::uint32_t *>();
     size_t num_samps = std::min(std::min(
         asio::buffer_size(buff)/io_type.size,
-        size_t(_max_tx_samples_per_packet)),
+        size_t(max_tx_samps_per_packet())),
         send_buff->size()/io_type.size
     );
 
@@ -148,7 +155,7 @@ size_t usrp2_impl::send(
     //copy-convert the samples into the send buffer
     convert_io_type_to_otw_type(
         asio::buffer_cast<const void*>(buff), io_type,
-        (void*)items, _otw_type,
+        (void*)items, _tx_otw_type,
         num_samps
     );
 
@@ -192,7 +199,7 @@ size_t usrp2_impl::recv(
 
     //copy-convert the samples from the recv buffer
     convert_otw_type_to_io_type(
-        (const void*)items, _otw_type,
+        (const void*)items, _rx_otw_type,
         asio::buffer_cast<void*>(buff), io_type,
         num_samps
     );
diff --git a/host/lib/usrp/usrp2/mboard_impl.cpp b/host/lib/usrp/usrp2/mboard_impl.cpp
index 9ae68d158..a10529102 100644
--- a/host/lib/usrp/usrp2/mboard_impl.cpp
+++ b/host/lib/usrp/usrp2/mboard_impl.cpp
@@ -111,7 +111,7 @@ void usrp2_impl::issue_ddc_stream_cmd(const stream_cmd_t &stream_cmd){
 
     //issue the stream command
     _iface->poke32(FR_RX_CTRL_STREAM_CMD, FR_RX_CTRL_MAKE_CMD(
-        (inst_samps)? stream_cmd.num_samps : ((inst_chain)? _max_rx_samples_per_packet : 1),
+        (inst_samps)? stream_cmd.num_samps : ((inst_chain)? max_rx_samps_per_packet() : 1),
         (stream_cmd.stream_now)? 1 : 0,
         (inst_chain)? 1 : 0,
         (inst_reload)? 1 : 0
diff --git a/host/lib/usrp/usrp2/usrp2_impl.cpp b/host/lib/usrp/usrp2/usrp2_impl.cpp
index 2b7bdeea2..3b7156802 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.cpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.cpp
@@ -211,11 +211,11 @@ void usrp2_impl::get(const wax::obj &key_, wax::obj &val){
         return;
 
     case DEVICE_PROP_MAX_RX_SAMPLES:
-        val = size_t(_max_rx_samples_per_packet);
+        val = max_rx_samps_per_packet();
         return;
 
     case DEVICE_PROP_MAX_TX_SAMPLES:
-        val = size_t(_max_tx_samples_per_packet);
+        val = max_tx_samps_per_packet();
         return;
 
     default: UHD_THROW_PROP_GET_ERROR();
diff --git a/host/lib/usrp/usrp2/usrp2_impl.hpp b/host/lib/usrp/usrp2/usrp2_impl.hpp
index c5b6af810..e2d37e512 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.hpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.hpp
@@ -125,21 +125,32 @@ private:
     void recv_raw(uhd::rx_metadata_t &);
     uhd::dict<boost::uint32_t, size_t> _tx_stream_id_to_packet_seq;
     uhd::dict<boost::uint32_t, size_t> _rx_stream_id_to_packet_seq;
+
+    /*******************************************************************
+     * Deal with the rx and tx packet sizes
+     ******************************************************************/
     static const size_t _mtu = 1500; //FIXME we have no idea
     static const size_t _hdrs = (2 + 14 + 20 + 8); //size of headers (pad, eth, ip, udp)
-    static const size_t _max_rx_samples_per_packet =
-        (_mtu - _hdrs)/sizeof(boost::uint32_t) -
-        USRP2_HOST_RX_VRT_HEADER_WORDS32 -
-        USRP2_HOST_RX_VRT_TRAILER_WORDS32
+    static const size_t _max_rx_bytes_per_packet =
+        _mtu - _hdrs -
+        USRP2_HOST_RX_VRT_HEADER_WORDS32*sizeof(boost::uint32_t) -
+        USRP2_HOST_RX_VRT_TRAILER_WORDS32*sizeof(boost::uint32_t)
     ;
-    static const size_t _max_tx_samples_per_packet =
-        (_mtu - _hdrs)/sizeof(boost::uint32_t) -
-        uhd::transport::vrt::max_header_words32
+    static const size_t _max_tx_bytes_per_packet =
+        _mtu - _hdrs -
+        uhd::transport::vrt::max_header_words32*sizeof(boost::uint32_t)
     ;
+    size_t max_rx_samps_per_packet(void){
+        return _max_rx_bytes_per_packet/(_rx_otw_type.width*2/8);
+    }
+    size_t max_tx_samps_per_packet(void){
+        return _max_tx_bytes_per_packet/(_tx_otw_type.width*2/8);
+    }
+
     uhd::transport::managed_recv_buffer::sptr _rx_smart_buff;
     boost::asio::const_buffer _rx_copy_buff;
     size_t _fragment_offset_in_samps;
-    uhd::otw_type_t _otw_type;
+    uhd::otw_type_t _rx_otw_type, _tx_otw_type;
     void io_init(void);
 
     //udp transports for control and data