From 5281c04d97da873b9ccb1a7332b655162fec02d0 Mon Sep 17 00:00:00 2001
From: Samuel Obuch <samuel.obuch@espressif.com>
Date: Wed, 30 Apr 2025 17:17:20 +0200
Subject: [PATCH] fix(sysview): do not use freertos ticks to prevent deadlock

---
 .../Sample/FreeRTOSV10.4/SEGGER_SYSVIEW_FreeRTOS.c         | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/components/app_trace/sys_view/Sample/FreeRTOSV10.4/SEGGER_SYSVIEW_FreeRTOS.c b/components/app_trace/sys_view/Sample/FreeRTOSV10.4/SEGGER_SYSVIEW_FreeRTOS.c
index 6754a322c8..679b40107f 100644
--- a/components/app_trace/sys_view/Sample/FreeRTOSV10.4/SEGGER_SYSVIEW_FreeRTOS.c
+++ b/components/app_trace/sys_view/Sample/FreeRTOSV10.4/SEGGER_SYSVIEW_FreeRTOS.c
@@ -108,7 +108,7 @@ static void _cbSendTaskList(void) {
 *    Called from SystemView when asked by the host, returns the
 *    current system time in micro seconds.
 */
-static U64 _cbGetTime(void) {
+__attribute__((unused)) static U64 _cbGetTime(void) {
   U64 Time;
 
   Time = xTaskGetTickCountFromISR();
@@ -260,7 +260,10 @@ void SYSVIEW_SendTaskInfo(U32 TaskID, const char* sName, unsigned Prio, U32 Stac
 */
 // Callbacks provided to SYSTEMVIEW by FreeRTOS
 const SEGGER_SYSVIEW_OS_API SYSVIEW_X_OS_TraceAPI = {
-  _cbGetTime,
+  /* Callback _cbGetTime locks xKernelLock inside xTaskGetTickCountFromISR, this can cause deadlock on multi-core.
+     To prevent deadlock, always lock xKernelLock before s_sys_view_lock. Omitting the callback here results in sending
+     SYSVIEW_EVTID_SYSTIME_CYCLES events instead of SYSVIEW_EVTID_SYSTIME_US */
+  NULL,
   _cbSendTaskList,
 };