Yes, we do, the hardware does it. Testcases:Counting the state changes is one thing but you should also generate error messages for them.
The usual test here is:
$ candump -td -e any,0:0,#FFFFFFFF
should report proper state changes, if you send messages with
1. no cable connected
2. CAN high and low short-circuited
Also downwards if the hardware error is gone and you continue to send messages.
root@rk3399-q7:~# candump -td -e any,0:0,#FFFFFFFF | head -n 1000
(000.000000) can0 178 [0]
(000.000410) can0 20000030 [8] 00 00 00 00 00 00 08 00 ERRORFRAME
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{8}{0}}
(000.000445) can0 20000030 [8] 00 00 00 00 00 00 10 00 ERRORFRAME
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{16}{0}}
(000.000425) can0 20000030 [8] 00 00 00 00 00 00 18 00 ERRORFRAME
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{24}{0}}
(000.000451) can0 20000030 [8] 00 00 00 00 00 00 20 00 ERRORFRAME
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{32}{0}}
(000.000429) can0 20000030 [8] 00 00 00 00 00 00 28 00 ERRORFRAME
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{40}{0}}
(000.000448) can0 20000030 [8] 00 00 00 00 00 00 30 00 ERRORFRAME
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{48}{0}}
(000.000433) can0 20000030 [8] 00 00 00 00 00 00 38 00 ERRORFRAME
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{56}{0}}
(000.000437) can0 20000030 [8] 00 00 00 00 00 00 40 00 ERRORFRAME
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{64}{0}}
(000.000443) can0 20000030 [8] 00 00 00 00 00 00 48 00 ERRORFRAME
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{72}{0}}
(000.000437) can0 20000030 [8] 00 00 00 00 00 00 50 00 ERRORFRAME
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{80}{0}}
(000.000498) can0 20000030 [8] 00 00 00 00 00 00 58 00 ERRORFRAME
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{88}{0}}
(000.000394) can0 20000034 [8] 00 0C 00 00 00 00 60 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning}
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{96}{0}}
(000.000433) can0 20000034 [8] 00 0C 00 00 00 00 68 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning}
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{104}{0}}
(000.000437) can0 20000034 [8] 00 0C 00 00 00 00 70 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning}
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{112}{0}}
(000.000443) can0 20000034 [8] 00 0C 00 00 00 00 78 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning}
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{120}{0}}
(000.000444) can0 20000034 [8] 00 3C 00 00 00 00 80 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{128}{0}}
(000.000495) can0 20000024 [8] 00 3C 00 00 00 00 80 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
no-acknowledgement-on-tx
error-counter-tx-rx{{128}{0}}
(000.000883) can0 20000034 [8] 00 3C 00 00 00 00 80 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
transceiver-status
no-acknowledgement-on-tx
error-counter-tx-rx{{128}{0}}
(000.000996) can0 20000004 [8] 00 0C 00 00 00 00 7F 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning}
error-counter-tx-rx{{127}{0}}
root@rk3399-q7:~# candump -td -e any,0:0,#FFFFFFFF | head -n 1000
(000.000000) can0 6AB [7] 33 39 62 29 00 F5 31
(000.000201) can0 20000018 [8] 00 00 08 00 00 00 18 00 ERRORFRAME
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{24}{0}}
(000.000141) can0 2000000C [8] 00 3C 08 00 00 00 88 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
error-counter-tx-rx{{136}{0}}
(000.000202) can0 2000001C [8] 00 3C 08 00 00 00 90 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{144}{0}}
(000.000174) can0 2000001C [8] 00 3C 08 00 00 00 98 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{152}{0}}
(000.000229) can0 2000001C [8] 00 3C 08 00 00 00 A0 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{160}{0}}
(000.000191) can0 2000001C [8] 00 3C 08 00 00 00 A8 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{168}{0}}
(000.000227) can0 2000001C [8] 00 3C 08 00 00 00 B0 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{176}{0}}
(000.000204) can0 2000001C [8] 00 3C 08 00 00 00 B8 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{184}{0}}
(000.000200) can0 2000001C [8] 00 3C 08 00 00 00 C0 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{192}{0}}
(000.000216) can0 2000001C [8] 00 3C 08 00 00 00 C8 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{200}{0}}
(000.000214) can0 2000001C [8] 00 3C 08 00 00 00 D0 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{208}{0}}
(000.000188) can0 2000001C [8] 00 3C 08 00 00 00 D8 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{216}{0}}
(000.000206) can0 2000001C [8] 00 3C 08 00 00 00 E0 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{224}{0}}
(000.000202) can0 2000001C [8] 00 3C 08 00 00 00 E8 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{232}{0}}
(000.000218) can0 2000001C [8] 00 3C 08 00 00 00 F0 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{240}{0}}
(000.000203) can0 2000001C [8] 00 3C 08 00 00 00 F8 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
transceiver-status
error-counter-tx-rx{{248}{0}}
(000.007153) can0 2000004C [8] 00 3C 08 00 00 00 F8 00 ERRORFRAME
controller-problem{rx-error-warning,tx-error-warning,rx-error-passive,tx-error-passive}
protocol-violation{{tx-dominant-bit-error}{}}
bus-off
error-counter-tx-rx{{248}{0}}