From 59eaec5dd6b058aad3fb5d2d33f99d7ea6653056 Mon Sep 17 00:00:00 2001
From: George Hotz <george@comma.ai>
Date: Fri, 14 Jun 2019 13:22:33 -0700
Subject: [PATCH] add volatiles to the ring buffer pointers

---
 board/drivers/can.h  | 4 ++--
 board/drivers/uart.h | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/board/drivers/can.h b/board/drivers/can.h
index 950e8f9e..195593a8 100644
--- a/board/drivers/can.h
+++ b/board/drivers/can.h
@@ -3,8 +3,8 @@
 //       CAN3_TX, CAN3_RX0, CAN3_SCE
 
 typedef struct {
-  uint32_t w_ptr;
-  uint32_t r_ptr;
+  volatile uint32_t w_ptr;
+  volatile uint32_t r_ptr;
   uint32_t fifo_size;
   CAN_FIFOMailBox_TypeDef *elems;
 } can_ring;
diff --git a/board/drivers/uart.h b/board/drivers/uart.h
index baba42e3..4ae4287e 100644
--- a/board/drivers/uart.h
+++ b/board/drivers/uart.h
@@ -2,11 +2,11 @@
 
 #define FIFO_SIZE 0x400
 typedef struct uart_ring {
-  uint16_t w_ptr_tx;
-  uint16_t r_ptr_tx;
+  volatile uint16_t w_ptr_tx;
+  volatile uint16_t r_ptr_tx;
   uint8_t elems_tx[FIFO_SIZE];
-  uint16_t w_ptr_rx;
-  uint16_t r_ptr_rx;
+  volatile uint16_t w_ptr_rx;
+  volatile uint16_t r_ptr_rx;
   uint8_t elems_rx[FIFO_SIZE];
   USART_TypeDef *uart;
   void (*callback)(struct uart_ring*);