FlexCAN asserts due to FreeRTOS nesting violation

[M_SCH]

Hello,

I have the following setup:

• S32DS v3.5.12
• RTD (P03, AR v4.7.0, SW v2.0.0)
• FreeRTOS 10.5.1 v2.0.0
• S32K148 MCU

I use a project that depends on the following drivers

• FlexCAN
• FreeRTOS
• BaseNXP (selects OsifFreeRtosType)
• others (may not be relevant to the potential bug)

When I debug the application I observe that it ends up in an assert statement through the following sequence of function calls:

1. ISR(CAN0_ORED_0_15_MB_IRQHandler)
1. RTD/src/FlexCAN_Ip_Irq.c at line 214
2. FlexCAN_IRQHandler( ... )
1. RTD/src/FlexCAN_Ip.c at line 2926
3. FlexCAN_IRQHandlerRxMB
1. RTD/src/FlexCAN_Ip.c at line 1342
4. can_RX_TX_callback
1. custom callback for to handle CAN RX/TX events, located inside the project folder
2. calls FlexCAN_Ip_Receive
5. FlexCAN_Ip_Receive
1. RTD/src/FlexCAN_Ip.c at line 2046
6. FlexCAN_SetMsgBuffIntCmd
1. RTD/src/FlexCAN_Ip_HwAccess.c at line 1053
7. SchM_Enter_Can_43_FLEXCAN_CAN_EXCLUSIVE_AREA_18
1. RTD/src/SchM_Can_43_FLEXCAN.c at line 1125
8. OsIf_SuspendAllInterrupts
1. RTD/include/OsIf_Internal.h at line 274
9. SuspendAllInterrupts
1. RTD/include/OsIf_Internal.h at line 247
10. taskENTER_CRITICAL
1. FreeRTOS/Source/Include/task.h at line 210
11. portENTER_CRITICAL
1. FreeRTOS/Source/portable/GCC/ARM_CM4F/portmacro.h at line 105
12. vPortEnterCritical
1. FreeRTOS/Source/portable/GCC/ARM_CM4F/port.c at line 425
2. configASSERT

See also the debug session call sequence

Now I found a similar ticket where one NXP tech-support employee labels this issue as a bug, which may be resolved in a future RTD package release.

To be sure, can you

1. confirm that this is a bug in the RTD driver
2. present a workaround
   1. I have tried to replace the portENTER_CRITICAL call by portENTER_CRITICAL_FROM_ISR (same for the EXIT version) in the local RTD folder in the header file Osif_Internal.h and in the RTD installation folder (S32DS.3.5\S32DS\software\PlatformSDK_S32K1_S32M24\RTD\BaseNXP_TS_T40D2M20I0R0\include\Osif_Internal.h)
      But then I get another build error (Description Resource Path Location Type
      too few arguments to function 'vPortSetBASEPRI' portmacro.h /__FreeRTOS_Toggle_Led_Example_S32K148__/FreeRTOS/Source/portable/GCC/ARM_CM4F line 102 C/C++ Problem)
      
3. point out if this is resolved by the RTD P04 package or when you plan to release package which fixes this isse

Best regards,

M_SCH

[PetrS · Accepted solution]

Hi,

yes, this is RTD issue and will be fixed with next RTD release. It should be version 3.0.0, not sure of the release plan.
Not able to comment more.

BR, Petr

[M_SCH]

Hello,

one more thing.

My current implementation relies on the FlexCAN_Ip_Receive function using interrupts. Which of the following options would you recommend for a temporary fix:

1. Modify the Osif_Internal.h file (so that it matches the implementation of the RTD AR 4.4.0, SW 1.0.0):

#define ResumeAllInterrupts()   ASM_KEYWORD(" cpsie i")
#define SuspendAllInterrupts()  ASM_KEYWORD(" cpsid i")​

2. Use FlexCAN_Ip_ReceiveBlocking - keep in mind that I have multiple message buffers to query.

Best regards,

M_SCH

[M_SCH]

Hello Petr,

thanks for the information!

Best regards, M_SCH