diff --git a/board/can.h b/board/can.h
index 81233e17..0a395bf9 100644
--- a/board/can.h
+++ b/board/can.h
@@ -100,8 +100,10 @@ void can_init(uint8_t bus_number) {
   CAN->FMR &= ~(CAN_FMR_FINIT);
 
   // enable all CAN interrupts
-  CAN->IER = 0xFFFFFFFF;
+  //CAN->IER = 0xFFFFFFFF;
   //CAN->IER = CAN_IER_TMEIE | CAN_IER_FMPIE0 | CAN_IER_FMPIE1;
+  //CAN->IER = CAN_IER_TMEIE;
+  CAN->IER = CAN_IER_TMEIE | CAN_IER_FMPIE0;
 }
 
 void can_init_all() {
diff --git a/board/main.c b/board/main.c
index d1ed6a13..a40fd53f 100644
--- a/board/main.c
+++ b/board/main.c
@@ -50,26 +50,36 @@ can_ring *can_queues[] = {&can_tx1_q, &can_tx2_q, &can_tx3_q};
 // ********************* interrupt safe queue *********************
 
 int pop(can_ring *q, CAN_FIFOMailBox_TypeDef *elem) {
+  int ret = 0;
+
+  __disable_irq();
   if (q->w_ptr != q->r_ptr) {
     *elem = q->elems[q->r_ptr];
     if ((q->r_ptr + 1) == q->fifo_size) q->r_ptr = 0;
     else q->r_ptr += 1;
-    return 1;
+    ret = 1;
   }
-  return 0;
+  __enable_irq();
+
+  return ret;
 }
 
 int push(can_ring *q, CAN_FIFOMailBox_TypeDef *elem) {
+  int ret = 0;
   uint32_t next_w_ptr;
+
+  __disable_irq();
   if ((q->w_ptr + 1) == q->fifo_size) next_w_ptr = 0;
   else next_w_ptr = q->w_ptr + 1;
   if (next_w_ptr != q->r_ptr) {
     q->elems[q->w_ptr] = *elem;
     q->w_ptr = next_w_ptr;
-    return 1;
+    ret = 1;
   }
+  __enable_irq();
+
   puts("push failed!\n");
-  return 0;
+  return ret;
 }
 
 // ***************************** serial port queues *****************************
@@ -254,13 +264,26 @@ void process_can(uint8_t can_number) {
   #endif
 
   // add successfully transmitted message to my fifo
-  if ((CAN->TSR & CAN_TSR_TXOK0) == CAN_TSR_TXOK0) {
-    CAN_FIFOMailBox_TypeDef to_push;
-    to_push.RIR = CAN->sTxMailBox[0].TIR;
-    to_push.RDTR = (CAN->sTxMailBox[0].TDTR & 0xFFFF000F) | ((CAN_BUS_RET_FLAG | bus_number) << 4);
-    to_push.RDLR = CAN->sTxMailBox[0].TDLR;
-    to_push.RDHR = CAN->sTxMailBox[0].TDHR;
-    push(&can_rx_q, &to_push);
+  if ((CAN->TSR & CAN_TSR_RQCP0) == CAN_TSR_RQCP0) {
+    if ((CAN->TSR & CAN_TSR_TXOK0) == CAN_TSR_TXOK0) {
+      CAN_FIFOMailBox_TypeDef to_push;
+      to_push.RIR = CAN->sTxMailBox[0].TIR;
+      to_push.RDTR = (CAN->sTxMailBox[0].TDTR & 0xFFFF000F) | ((CAN_BUS_RET_FLAG | bus_number) << 4);
+      to_push.RDLR = CAN->sTxMailBox[0].TDLR;
+      to_push.RDHR = CAN->sTxMailBox[0].TDHR;
+      push(&can_rx_q, &to_push);
+    }
+
+    if ((CAN->TSR & CAN_TSR_TERR0) == CAN_TSR_TERR0) {
+      puts("CAN TX ERROR!\n");
+    }
+
+    if ((CAN->TSR & CAN_TSR_ALST0) == CAN_TSR_ALST0) {
+      puts("CAN TX ARBITRATION LOST!\n");
+    }
+
+    // clear interrupt
+    CAN->TSR |= CAN_TSR_RQCP0;
   }
 
   // check for empty mailbox
@@ -274,9 +297,6 @@ void process_can(uint8_t can_number) {
       CAN->sTxMailBox[0].TIR = to_send.RIR;
     }
   }
-
-  // clear interrupt
-  CAN->TSR |= CAN_TSR_RQCP0;
 }
 
 void send_can(CAN_FIFOMailBox_TypeDef *to_push, uint8_t bus_number);
@@ -311,7 +331,6 @@ void can_rx(uint8_t can_number) {
 
     // modify RDTR for our API
     to_push.RDTR = (to_push.RDTR & 0xFFFF000F) | (bus_number << 4);
-
     safety_rx_hook(&to_push);
 
     #ifdef PANDA
diff --git a/panda/__init__.py b/panda/__init__.py
index 51d116b0..b9a4363c 100644
--- a/panda/__init__.py
+++ b/panda/__init__.py
@@ -113,9 +113,9 @@ class Panda(object):
       cmd = "make clean"
     else:
       cmd = "true"
-    os.system("cd %s && %s && make" % (os.path.join(BASEDIR, "board"), cmd))
-    # TODO: check for errors
+    ret = os.system("cd %s && %s && make" % (os.path.join(BASEDIR, "board"), cmd))
     time.sleep(1)
+    return ret==0
 
   @staticmethod
   def list():
diff --git a/tests/automated/usb_to_can.py b/tests/automated/usb_to_can.py
index bcf52aa0..ea1b4d84 100644
--- a/tests/automated/usb_to_can.py
+++ b/tests/automated/usb_to_can.py
@@ -8,7 +8,7 @@ from nose.tools import timed, assert_equal, assert_less, assert_greater
 # must run first
 def test_build_download_connect():
   # download the latest code
-  Panda.program(True)
+  assert(Panda.program(True))
 
   # connect to the panda
   p = Panda()
@@ -81,19 +81,24 @@ def test_reliability():
   p.set_can_loopback(True)
   p.set_can_speed_kbps(0, 1000)
 
+  addrs = range(100, 100+MSG_COUNT)
+  ts = [(j, 0, "\xaa"*8, 0) for j in addrs]
+
   # 100 loops
   for i in range(LOOP_COUNT):
     st = time.time()
-    p.can_send_many([(0x1aa, 0, "\xaa"*8, 0)]*MSG_COUNT)
+
+    p.can_send_many(ts)
     r = []
-    while len(r) < 200 and (time.time() - st) < 3:
+    while len(r) < 200 and (time.time() - st) < 0.5:
       r.extend(p.can_recv())
 
     sent_echo = filter(lambda x: x[3] == 0x80, r)
     loopback_resp = filter(lambda x: x[3] == 0, r)
 
-    assert_equal(len(sent_echo), 100)
-    assert_equal(len(loopback_resp), 100)
+    assert_equal(sorted(map(lambda x: x[0], loopback_resp)), addrs)
+    assert_equal(sorted(map(lambda x: x[0], sent_echo)), addrs)
+    assert_equal(len(r), 200)
 
     # take sub 20ms
     et = (time.time()-st)*1000.0