From bd990f7bd864e2edb6402ac4f12a03de0044707e Mon Sep 17 00:00:00 2001
From: huangly <huangly@milesight.com>
Date: Fri, 31 May 2024 13:55:39 +0800
Subject: [PATCH] [LORA MAC] Prevent 32-bit data from overflowing and winding
 to cause RX receive window exception

---
 Middlewares/Third_Party/LoRaWAN/Mac/LoRaMac.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/Middlewares/Third_Party/LoRaWAN/Mac/LoRaMac.c b/Middlewares/Third_Party/LoRaWAN/Mac/LoRaMac.c
index 1d0631f7..44b5195b 100644
--- a/Middlewares/Third_Party/LoRaWAN/Mac/LoRaMac.c
+++ b/Middlewares/Third_Party/LoRaWAN/Mac/LoRaMac.c
@@ -1007,12 +1007,16 @@ static void ProcessRadioTxDone( void )
         Radio.Sleep( );
     }
 #if ( !defined(DISABLE_LORAWAN_RX_WINDOW) || (DISABLE_LORAWAN_RX_WINDOW == 0) )
+    // Setup timers
     // Setup timers
     CRITICAL_SECTION_BEGIN( );
-    uint32_t offset = TimerGetCurrentTime( ) - TxDoneParams.CurTime;
-    TimerSetValue( &MacCtx.RxWindowTimer1, MacCtx.RxWindow1Delay - offset );
+    uint32_t cur_time = TimerGetCurrentTime( );
+    uint32_t offset = (cur_time >= TxDoneParams.CurTime) ? (cur_time - TxDoneParams.CurTime) : (cur_time+ (0XFFFFFFFF - TxDoneParams.CurTime + 1));
+    uint32_t value1 = (MacCtx.RxWindow1Delay > offset) ? (MacCtx.RxWindow1Delay - offset) : MacCtx.RxWindow1Delay;
+    TimerSetValue( &MacCtx.RxWindowTimer1, value1 );
     TimerStart( &MacCtx.RxWindowTimer1 );
-    TimerSetValue( &MacCtx.RxWindowTimer2, MacCtx.RxWindow2Delay - offset );
+    uint32_t value2 = (MacCtx.RxWindow2Delay > offset) ? (MacCtx.RxWindow2Delay - offset) : MacCtx.RxWindow2Delay;
+    TimerSetValue( &MacCtx.RxWindowTimer2, value2 );
     TimerStart( &MacCtx.RxWindowTimer2 );
     CRITICAL_SECTION_END( );
 #else