Stack overflow in tickless mode with debug profile on NUCLEO-L476RG

[janjongboom]

Description

Same as #7222? This is on Mbed OS 5.9 (949cb49) with mbed-os-example-lorawan on NUCLEO-L476RG:

++ MbedOS Error Info ++
Error Status: 0x80020125 Code: 293 Module: 2
Error Message: CMSIS-RTOS error: Stack overflow
Location: 0x8015BF9
Error Value: 0x1
Current Thread: Id: 0x200020E8 Entry: 0x8015BAD StackSize: 0x200 StackMem: 0x20002178 SP: 0x10007EC0 
-- MbedOS Error Info --

Upping the idle thread stack size to 0x400 solves the issue.

Issue request type

[ ] Question
[ ] Enhancement
[X] Bug

[0xc0170]

cc @ARMmbed/team-st-mcd

[bcostm]

This stack size is defined in rtos/TARGET_CORTEX/mbed_rtx_conf.h

/** The idle thread's stack size can be configured by the application, if not explicitly specified, it'll default to 512 */
#ifndef MBED_CONF_APP_IDLE_THREAD_STACK_SIZE
#define MBED_CONF_APP_IDLE_THREAD_STACK_SIZE 512
#endif

As this value can be changed by the application I don't know what can we do on our side ?

[jeromecoutant]

Are you expecting something like:

#ifndef MBED_CONF_APP_IDLE_THREAD_STACK_SIZE
#ifdef MBED_TICKLESS
#define MBED_CONF_APP_IDLE_THREAD_STACK_SIZE 1024
#else
#define MBED_CONF_APP_IDLE_THREAD_STACK_SIZE 512
#endif
#endif

[janjongboom]

@bcostm I know that it can be set by the application, but enabling tickless (a supported feature) mode on a NUCLEO board (a supported board) should never return in an instant hard fault. I thought this was acknowledged and fixed in #7222. If we cannot reduce stack usage in debug builds when using tickless we should increase idle thread stack size as @jeromecoutant is suggesting (I'd rather optimize this in a way that it's not required, but OK).

[jeromecoutant]

Hi

For information, I am currently testing TICKLESS feature with NUCLEO-L476RG.
Tests are OK in default mode, but often crash in Stack overflow as soon as I added some stats (MBED_CPU_STATS_ENABLED in my case)...

Maybe ARM core experts can double check ?

Thx

[jeromecoutant]

@0xc0170 @deepikabhavnani

[adbridge]

Internal Jira reference: https://jira.arm.com/browse/IOTPART-6578

[jeromecoutant]

@c1728p9