topic Re: CAN0_ORed_Err_Wakeup_IRQHandler() is triggered and FLEXCAN_GetErrorCounters is returning 0 in S32K

CAN0_ORed_Err_Wakeup_IRQHandler() is triggered and FLEXCAN_GetErrorCounters is returning 0

ED86 — Fri, 26 May 2023 05:05:47 GMT

I am working with flexcan drivers on s32k116. I have a CAN network with 2 nodes in total. I was trying different test cases trying to test durability of drivers and related code. There was a case in which the CAN0_ORed_Err_Wakeup_IRQHandler() is being triggered but FLEXCAN_GetErrorCounters(base) is returning 0. Also, other interrupts are not being triggered during this case as the CAN0_ORed_Err_Wakeup_IRQHandler() is triggered again and again.

I have attached screenshots of callstack from IDE and the snippet where the FLEXCAN_GetErrorCounters(base) is being used by driver layer.

Re: CAN0_ORed_Err_Wakeup_IRQHandler() is triggered and FLEXCAN_GetErrorCounters is returning 0

PetrS — Mon, 29 May 2023 08:44:26 GMT

Hi,

what s32ds and SDK version are you using?
I can imagine a case with ECR is zero when module recovers from bus off state. So it would be better to check rather errors flags for which error interrupt is enabled instead of ECR.
If you read ESR1 in your situation which one are set?

BR, Petr

Re: CAN0_ORed_Err_Wakeup_IRQHandler() is triggered and FLEXCAN_GetErrorCounters is returning 0

ED86 — Fri, 02 Jun 2023 07:40:53 GMT

Thank you for your reply. Apparently following things were found.

1. Interrupt bit was being set in ESR1 and ECR was 0 in SDK due to which Error handler was not being called and Interrupt was not being cleared.

2. Interrupt was being cleared only by '|=' operation and not by '=' in "FLEXCAN_ClearErrIntStatusFlag".

Both of these things were found in SDK v3.0.2 and v4.0.3

Re: CAN0_ORed_Err_Wakeup_IRQHandler() is triggered and FLEXCAN_GetErrorCounters is returning 0

PetrS — Fri, 09 Jun 2023 11:21:09 GMT

Hi,

1) here a driver is not ideally written for K11x devices, flags should be checks instead of error counter. However a reading ESR1 clears error status bits, so should be properly handled.

2) '|=' operation should not be used for flag clearing. Do you see it in driver somewhere?

BR, Petr