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ISR does not context switch out to its respective task using freeRTOS

CLeo.1
Senior II

Hi everyone, first time using freeRTOS and everything is working besides context switching from an ISR.

The STM32H743ZI has DMA (DMA1_Stream0) setup as UART Rx. This triggers an ISR that sends a queue for task synchronization, as the task that receive the queue will now process the data within the DMA Rx buffer.

Issue is the code gets hung up at "xQueueSendFromISR(CLIQueue, &temp, 0);"

The task priority is = 2 and its the only task in the system thus far

Configuration that I used/done

I am using freeRTOS Version: "V10.4.4+" Located in task.h

PORT: GCC/ARM_CM4F

HEAP: Using Heap 4

Language: C++

Note I also commented out "stm32h7xx_it.c" as there were duplicates of the handlers

Any guidance would be grateful

FreeRTOSConfig.h:

/*
 * FreeRTOS V202107.00
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * http://www.FreeRTOS.org
 * http://aws.amazon.com/freertos
 *
 * 1 tab == 4 spaces!
 */
 
#ifndef FREERTOS_CONFIG_H
#define FREERTOS_CONFIG_H
 
/*-----------------------------------------------------------
 * Application specific definitions.
 *
 * These definitions should be adjusted for your particular hardware and
 * application requirements.
 *
 * THESE PARAMETERS ARE DESCRIBED WITHIN THE 'CONFIGURATION' SECTION OF THE
 * FreeRTOS API DOCUMENTATION AVAILABLE ON THE FreeRTOS.org WEB SITE.
 *
 * See http://www.freertos.org/a00110.html.
 *----------------------------------------------------------*/
 
/* Ensure definitions are only used by the compiler, and not by the assembler. */
#if defined(__ICCARM__) || defined(__CC_ARM) || defined(__GNUC__)
  #include <stdint.h>
  extern uint32_t SystemCoreClock;
#endif
 
#define configUSE_PREEMPTION					1
#define configSUPPORT_STATIC_ALLOCATION			1
#define configSUPPORT_DYNAMIC_ALLOCATION		1
#define configUSE_IDLE_HOOK						0
#define configUSE_TICK_HOOK						0
#define configCPU_CLOCK_HZ						( 480e6)
#define configTICK_RATE_HZ						( ( TickType_t ) 1000 )
#define configMAX_PRIORITIES					( 56 )
#define configMINIMAL_STACK_SIZE				( ( uint16_t ) 512 )
#define configTOTAL_HEAP_SIZE					( ( size_t ) 15 * 1024 )
#define configMAX_TASK_NAME_LEN					( 16 )
#define configUSE_TRACE_FACILITY				1
#define configUSE_16_BIT_TICKS					0
#define configUSE_MUTEXES						1
#define configQUEUE_REGISTRY_SIZE				8
#define configUSE_RECURSIVE_MUTEXES				1
#define configUSE_COUNTING_SEMAPHORES			1
#define configUSE_PORT_OPTIMISED_TASK_SELECTION	0
#define configUSE_MALLOC_FAILED_HOOK			1
#define configCHECK_FOR_STACK_OVERFLOW			2
 
/* Defaults to size_t for backward compatibility, but can be changed
 * if lengths will always be less than the number of bytes in a size_t. */
#define configMESSAGE_BUFFER_LENGTH_TYPE		size_t
/* USER CODE END MESSAGE_BUFFER_LENGTH_TYPE */
 
/* Software timer definitions. */
#define configUSE_TIMERS						1
#define configTIMER_TASK_PRIORITY				( 2 )
#define configTIMER_QUEUE_LENGTH				10
#define configTIMER_TASK_STACK_DEPTH			256
 
/* Set the following definitions to 1 to include the API function, or zero
 * to exclude the API function. */
#define INCLUDE_vTaskPrioritySet				1
#define INCLUDE_uxTaskPriorityGet				1
#define INCLUDE_vTaskDelete						1
#define INCLUDE_vTaskCleanUpResources			0
#define INCLUDE_vTaskSuspend					1
#define INCLUDE_vTaskDelayUntil					1
#define INCLUDE_vTaskDelay						1
#define INCLUDE_xTaskGetSchedulerState			1
#define INCLUDE_xTimerPendFunctionCall			1
#define INCLUDE_xQueueGetMutexHolder			1
#define INCLUDE_uxTaskGetStackHighWaterMark		1
#define INCLUDE_eTaskGetState					1
 
/* Cortex-M specific definitions. */
#ifdef __NVIC_PRIO_BITS
	/* __BVIC_PRIO_BITS will be specified when CMSIS is being used. */
	#define configPRIO_BITS						__NVIC_PRIO_BITS
#else
	#define configPRIO_BITS						4
#endif
 
/* The lowest interrupt priority that can be used in a call to a "set priority"
 * function. */
#define configLIBRARY_LOWEST_INTERRUPT_PRIORITY	15
 
/* The highest interrupt priority that can be used by any interrupt service
 * routine that makes calls to interrupt safe FreeRTOS API functions.  DO NOT
 * CALL INTERRUPT SAFE FREERTOS API FUNCTIONS FROM ANY INTERRUPT THAT HAS A
 * HIGHER PRIORITY THAN THIS! (higher priorities are lower numeric values. */
#define configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY 5
 
/* Interrupt priorities used by the kernel port layer itself.  These are generic
 * to all Cortex-M ports, and do not rely on any particular library functions. */
#define configKERNEL_INTERRUPT_PRIORITY				( configLIBRARY_LOWEST_INTERRUPT_PRIORITY << ( 8 - configPRIO_BITS ) )
/* !!!! configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to zero !!!!
See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html. */
#define configMAX_SYSCALL_INTERRUPT_PRIORITY		( configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY << ( 8 - configPRIO_BITS ) )
 
/* Normal assert() semantics without relying on the provision of an assert.h
 * header file. */
#define configASSERT( x )							if ( ( x ) == 0 ) { taskDISABLE_INTERRUPTS(); for( ;; ); }
 
/* Definitions that map the FreeRTOS port interrupt handlers to their CMSIS
 * standard names. */
#define vPortSVCHandler								SVC_Handler
#define xPortPendSVHandler							PendSV_Handler
#define xPortSysTickHandler							SysTick_Handler
 
/* Allow system call from within FreeRTOS kernel only. */
#define configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY	1
 
/* STM32H743 has 16 MPU regions and therefore it is necessary to configure
 * configTOTAL_MPU_REGIONS correctly. */
#define configTOTAL_MPU_REGIONS						16
 
/* The default TEX,S,C,B setting marks the SRAM as shareable and as a result,
 * disables cache. Do not mark the SRAM as shareable because caching is being
 * used. TEX=0, S=0, C=1, B=1. */
#define configTEX_S_C_B_SRAM						( 0x03UL )
 
#endif /* FREERTOS_CONFIG_H */

Code: ISR

extern "C" void DMA1_Stream0_IRQHandler() {
 
    uint8_t temp = 1;
    LL_DMA_ClearFlag_TC0(DMA1);
    xQueueSendFromISR(CLIQueue, &temp, 0);
    portYIELD_FROM_ISR();
}

Code: TASK

void processCLITask(void * p) {
 
    uint8_t temp;
 
    while(1) {
 
        xQueueReceive(CLIQueue, &temp, portMAX_DELAY);
        //Logic
    }
 
}

6 REPLIES 6
KnarfB
Principal III

What is your ISR priority, see comment for configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY

Ahhh, the NVIC handler is at currently 0, so I guess thats the highest which is higher than 0. So I gotta replace that 5 with a zero I guess? and change my nvic interrupt to anything else besides 0?

Nevermind, I cant make it zero, but I guess just change the NVIC prio to anything > 5?

right, should work.

Ill check once I am home, thank you amigo

Alright, back home and tested.

So, it no longer gets stuck there, however its now directing to a fault handler saying this  

 .section .text.Default_Handler,"ax",%progbits

Default_Handler:

Infinite_Loop:

 b Infinite_Loop

 .size Default_Handler, .-Default_Handler

located in startup_stm32h743zitx.s

and MCU program seize to stop