s32k144:FLEXCAN_IRQHandler issue

[gumu]

Dear Sir,

Recently, on our project, we encountered an issue related to FlexCAN interrupts. Here's a description of the phenomenon:

On CAN instance 2, we have configured 14 message buffers (MBs) for receiving messages. After a period of testing, it was discovered that the entire RTOS task scheduling had become unresponsive.

Through breakpoints, we found that the system was continuously processing the FLEXCAN_IRQHandler. Further debugging revealed that the corresponding message buffer interrupt was active, but the status of the message buffer was FLEXCAN_MB_IDLE. This resulted in the inability of FLEXCAN_IRQHandler to clear the interrupt flag for that specific message buffer, which potentially caused the continuous invocation of FLEXCAN_IRQHandler and prevented the system from handling other interrupts.

Here's an overview of how the message buffers were being used during the issue reproduction:

Could you please provide some debugging suggestions?

Thanks！

[gumu]

update SDK version info:

s32k144_sdk 3.0.0

[PetrS · Accepted solution]

Hi,

later SDK versions (from SDK4.0.x) fixed this behavior with possible trapping in ISR loop, as far as I know. Below is code from 4.0.3 version...

So please update to latest SDK.

BR, Petr

[gumu]

Hi @PetrS ,

Thank you for your support! I just updated the code and the issue did not reoccur.