Occasional CAN error-passive event

Dear CAN experts,

we’re facing a CAN issue we cannot quite make sense of. In general our setup works great and we did not notice this lingering issue until now. We use L4T 32.5.1 and talk to multiple CAN nodes. About once every other minute we can observe a short burst of errors that leads to the CAN bus entering error-passive mode for a couple 100ms before it recovers (berr-counter tx reaches 127):

[Jan27 08:15] mttcan_handle_bus_err: 408 callbacks suppressed
[  +0.000151] mttcan c310000.mttcan can0: Acknowledgement Error Detected
[  +0.000155] mttcan c310000.mttcan can0: IR 0x8400000 PSR 0x71b
[  +0.000170] mttcan c310000.mttcan can0: Acknowledgement Error Detected
[  +0.000119] mttcan c310000.mttcan can0: IR 0x8400000 PSR 0x71b
[  +0.000172] mttcan c310000.mttcan can0: Acknowledgement Error Detected
[  +0.000137] mttcan c310000.mttcan can0: IR 0x8400000 PSR 0x71b
[  +0.000399] mttcan c310000.mttcan can0: Acknowledgement Error Detected
[  +0.000130] mttcan c310000.mttcan can0: IR 0x8400000 PSR 0x71b
[  +0.000244] mttcan c310000.mttcan can0: Acknowledgement Error Detected
[  +0.000139] mttcan c310000.mttcan can0: IR 0x8400000 PSR 0x71b
[  +0.001017] mttcan c310000.mttcan can0: entered error warning state
[  +0.000989] mttcan c310000.mttcan can0: entered error passive state

The dmesg output above is one full error-passive event. After that no more errors occur until the next event of this kind 1-2 minutes later. We run the CAN bus with 500kbit:

$ ip -details -statistics link show can0
11: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 10
    link/can  promiscuity 0
    can <BERR-REPORTING> state ERROR-ACTIVE (berr-counter tx 7 rx 0) restart-ms 1000
          bitrate 498701 sample-point 0.870
          tq 26 prop-seg 33 phase-seg1 33 phase-seg2 10 sjw 1
          mttcan: tseg1 2..255 tseg2 0..127 sjw 1..127 brp 1..511 brp-inc 1
          mttcan: dtseg1 1..31 dtseg2 0..15 dsjw 1..15 dbrp 1..15 dbrp-inc 1
          clock 38400000
          re-started bus-errors arbit-lost error-warn error-pass bus-off
          0          432673     0          1070       1610       0         numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
    RX: bytes  packets  errors  dropped overrun mcast
    32477736   4059717  432673  0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    4195328    524416   0       0       0       0

Any hints to what could be wrong are highly appreciated! Also I’d like to understand what this line means:

[  +0.000149] mttcan c310000.mttcan can0: IR 0x8000000 PSR 0x71b

Thanks a lot,
Jonas

There is no update from you for a period, assuming this is not an issue any more.
Hence we are closing this topic. If need further support, please open a new one.
Thanks

Sorry for the late response, is this still an issue to support? Thanks

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