driver: error interrupt: EPI vs ctu_can_fd_read_error_state race condition
When receiving EPI interrupt (error passive or bus off), it means that the controller is or was in that state. So when checking state afterwards, it should be like this:
- state is ERROR_PASSIVE -> obviously we are EP
- state is BUS_OFF -> we are bus off and the controller stays there until reset
- state is ERROR_WARNING or ERROR_ACTIVE -> the controller was in EP, but now it is not; we should emit EP error info nonetheless, because the condition occured.
TODO: In case 3 (EPI + EW), should we announce the current EW state or not?
TODO2: Is EWI triggered only when the error counter is increased into EW zone, or also it it is decreased from EP to EW?