boardd: keep same offset for now

selfdrive/boardd/boardd.cc

@@ -144,7 +144,7 @@ bool safety_setter_thread(std::vector<Panda *> pandas) {
 Panda *connect(std::string serial="", uint32_t index=0) {
   std::unique_ptr<Panda> panda;
   try {
-    panda = std::make_unique<Panda>(serial, (index * PANDA_BUS_CNT));
+    panda = std::make_unique<Panda>(serial, (index * PANDA_BUS_OFFSET));
   } catch (std::exception &e) {
     return nullptr;
   }

selfdrive/boardd/panda.cc

@@ -172,7 +172,7 @@ void Panda::pack_can_buffer(const capnp::List<cereal::CanData>::Reader &can_data
   for (auto cmsg : can_data_list) {
     // check if the message is intended for this panda
     uint8_t bus = cmsg.getSrc();
-    if (bus < bus_offset || bus >= (bus_offset + PANDA_BUS_CNT)) {
+    if (bus < bus_offset || bus >= (bus_offset + PANDA_BUS_OFFSET)) {
       continue;
     }
     auto can_data = cmsg.getDat();

selfdrive/boardd/panda.h

@@ -23,6 +23,8 @@
 #define CAN_REJECTED_BUS_OFFSET   0xC0U
 #define CAN_RETURNED_BUS_OFFSET 0x80U
 
+#define PANDA_BUS_OFFSET 4
+
 struct __attribute__((packed)) can_header {
   uint8_t reserved : 1;
   uint8_t bus : 3;

selfdrive/boardd/tests/test_boardd_usbprotocol.cc

@@ -40,7 +40,7 @@ PandaTest::PandaTest(uint32_t bus_offset_, int can_list_size, cereal::PandaState
     uint32_t id = util::random_int(0, std::size(dlc_to_len) - 1);
     const std::string &dat = test_data[dlc_to_len[id]];
     can.setAddress(i);
-    can.setSrc(util::random_int(0, 3) + bus_offset);
+    can.setSrc(util::random_int(0, 2) + bus_offset);
     can.setDat(kj::ArrayPtr((uint8_t *)dat.data(), dat.size()));
     total_pakets_size += sizeof(can_header) + dat.size();
   }