Hi Wolfgang,
On 03/14/2017 08:11 AM, Wolfgang Grandegger wrote:
... snip ...
A few other things to check:
Run "cangen" and monitor the message with "candump -e any,0:0,#FFFFFFF".
Then 1) disconnect the cable or 2) short-circuit CAN low and high at the
connector. You should see error messages. After reconnection or removing
the short-circuit (and bus-off recovery) the state should go back to
"active".
With the above sequence, candump reports "ERRORFRAME" with
protocol-violation{{}{acknowledge-slot}}, bus-error. On re-connecting
the cable the can state goes back to ACTIVE and I see the messages that
were in the queue being sent.
Do you get the ACK error also with berr-reporting off? Would be nice if
you could show a candump log here.
Below is a log for disconnecting and re-connecting CAN cable scenario:
(Note this is on a 4.1.18 kernel with RT patch)
root@imx6qrom5420b1:~# ip link set can0 up type can bitrate 1000000
berr-reporting on
root@imx6qrom5420b1:~# candump -e any,0:0,#FFFFFFF &
[1] 768
root@imx6qrom5420b1:~# cangen can0
can0 21C [8] 35 98 C0 7A 95 03 E6 2A
can0 6E6 [1] F2
can0 5C7 [2] 42 50
can0 57C [8] 83 7A E4 0C 03 8B 90 45
can0 55C [8] B9 74 87 52 D8 F4 64 04
can0 014 [8] 28 CB 96 57 3B 80 67 4F
can0 6AF [1] 35
can0 51E [8] B6 C8 6C 1D 3A 87 ED 2E
can0 527 [8] D0 8A D3 59 0E 34 40 78
can0 30C [2] 6A 12
can0 145 [8] CB 6E FF 55 C1 BE C3 22
can0 5A5 [8] C4 49 54 68 02 63 F9 35
can0 0BA [8] DA 57 5E 3A CE 88 20 1C
can0 516 [2] 09 09
can0 743 [8] 7C 4D 25 47 61 4C 56 3D
can0 31D [2] 9C D3
can0 71E [8] 53 7C 97 2A 2A F2 9F 56
can0 52E [8] FE DA 2D 51 73 96 DF 79
/////disconnect cable
can0 20000088 [8] 00 00 00 19 00 00 28 00 ERRORFRAME
protocol-violation{{}{acknowledge-slot}}
bus-error
error-counter-tx-rx{{40}{0}}
can0 20000088 [8] 00 00 00 19 00 00 58 00 ERRORFRAME
protocol-violation{{}{acknowledge-slot}}
bus-error
error-counter-tx-rx{{88}{0}}
can0 20000088 [8] 00 00 00 19 00 00 80 00 ERRORFRAME
protocol-violation{{}{acknowledge-slot}}
bus-error
error-counter-tx-rx{{128}{0}}
can0 2000008C [8] 00 20 00 19 00 00 80 00 ERRORFRAME
controller-problem{tx-error-passive}
protocol-violation{{}{acknowledge-slot}}
bus-error
error-counter-tx-rx{{128}{0}}
write: No buffer space available
root@imx6qrom5420b1:~# ip -s -d link show can0
4: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN
mode DEFAULT group default qlen 10
link/can promiscuity 0
can <BERR-REPORTING> state ERROR-PASSIVE (berr-counter tx 128 rx 0)
restart-ms 0
bitrate 1000000 sample-point 0.750
tq 62 prop-seg 5 phase-seg1 6 phase-seg2 4 sjw 1
hi3110: tseg1 2..16 tseg2 2..8 sjw 1..4 brp 1..64 brp-inc 1
clock 16000000
re-started bus-errors arbit-lost error-warn error-pass bus-off
0 6 0 1 1 0
RX: bytes packets errors dropped overrun mcast
0 0 6 0 0 0
TX: bytes packets errors dropped carrier collsns
106 18 0 0 0 0
root@imx6qrom5420b1:~#
/////re-connect cable
can0 169 [8] 35 55 A3 1C 0F 47 2E 5B
can0 318 [8] 11 AA 27 11 D2 1B CE 34
can0 577 [8] A0 A4 EE 50 8D A2 E1 3E
can0 4ED [8] 52 96 17 7E 31 FC 7D 7C
can0 2E7 [8] 92 48 D4 39 05 1E 9F 50
can0 200 [8] 4A 66 F6 02 1E 71 8E 26
can0 29A [8] 49 63 2E 7D C9 77 85 7A
can0 15A [7] 3C 0E 65 74 C3 62 80
can0 011 [1] D2
can0 26B [3] FC D6 68
can0 5CE [8] 6F 02 B5 14 BC 7A D7 02
root@imx6qrom5420b1:~# ip -s -d link show can0
4: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN
mode DEFAULT group default qlen 10
link/can promiscuity 0
can <BERR-REPORTING> state ERROR-ACTIVE (berr-counter tx 117 rx 0)
restart-ms 0
bitrate 1000000 sample-point 0.750
tq 62 prop-seg 5 phase-seg1 6 phase-seg2 4 sjw 1
hi3110: tseg1 2..16 tseg2 2..8 sjw 1..4 brp 1..64 brp-inc 1
clock 16000000
re-started bus-errors arbit-lost error-warn error-pass bus-off
0 7 0 1 1 0
RX: bytes packets errors dropped overrun mcast
0 0 7 0 0 0
TX: bytes packets errors dropped carrier collsns
181 29 0 0 0 0
//Reboot the board and test with bus error reporting off
root@imx6qrom5420b1:~# ip link set can0 up type can bitrate 1000000
berr-reporting off
root@imx6qrom5420b1:~# candump -e any,0:0,#FFFFFFF &
[1] 782
root@imx6qrom5420b1:~# cangen can0
can0 1FA [3] C9 FE C2
can0 3E2 [5] 85 37 03 5B 6F
can0 289 [8] A4 F6 BF 4A 3F 70 65 1B
can0 12D [8] B2 72 10 33 AB B4 68 64
can0 054 [2] 01 D7
can0 4A6 [8] 29 7D 76 56 CA C1 60 00
can0 768 [8] 97 3D 92 08 61 C1 D9 03
can0 098 [6] A4 A8 5A 60 92 1A
can0 3C9 [8] 71 78 0D 25 AB 27 8B 51
/////disconnect cable
write: No buffer space available
root@imx6qrom5420b1:~# ip -s -d link show can0
4: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN
mode DEFAULT group default qlen 10
link/can promiscuity 0
can state ERROR-ACTIVE (berr-counter tx 128 rx 0) restart-ms 0
bitrate 1000000 sample-point 0.750
tq 62 prop-seg 5 phase-seg1 6 phase-seg2 4 sjw 1
hi3110: tseg1 2..16 tseg2 2..8 sjw 1..4 brp 1..64 brp-inc 1
clock 16000000
re-started bus-errors arbit-lost error-warn error-pass bus-off
0 0 0 0 0 0
RX: bytes packets errors dropped overrun mcast
0 0 0 0 0 0
TX: bytes packets errors dropped carrier collsns
56 9 0 0 0 0
root@imx6qrom5420b1:~#
/////re-connect cable
can0 20000088 [8] 00 00 00 19 00 00 7F 00 ERRORFRAME
protocol-violation{{}{acknowledge-slot}}
bus-error
error-counter-tx-rx{{127}{0}}
can0 553 [6] 1A E4 60 6B DC 07
can0 7E3 [8] 1C 78 95 6E 10 81 AA 40
can0 20C [8] BB 35 13 25 60 0A 56 57
can0 1D0 [8] 48 4A 39 64 76 E6 57 08
can0 43A [1] 40
can0 2CF [7] 03 45 5E 0F 67 33 4C
can0 1CD [8] F9 4D AB 1D 96 A5 67 0E
can0 515 [8] 41 CD F2 5F 68 92 43 16
can0 661 [8] 45 9A 73 69 45 EE 8B 42
can0 41B [1] 55
can0 52F [1] 87
root@imx6qrom5420b1:~# ip -s -d link show can0
4: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN
mode DEFAULT group default qlen 10
link/can promiscuity 0
can state ERROR-ACTIVE (berr-counter tx 117 rx 0) restart-ms 0
bitrate 1000000 sample-point 0.750
tq 62 prop-seg 5 phase-seg1 6 phase-seg2 4 sjw 1
hi3110: tseg1 2..16 tseg2 2..8 sjw 1..4 brp 1..64 brp-inc 1
clock 16000000
re-started bus-errors arbit-lost error-warn error-pass bus-off
0 1 0 0 0 0
RX: bytes packets errors dropped overrun mcast
0 0 1 0 0 0
TX: bytes packets errors dropped carrier collsns
120 20 0 0 0 0
Also, any error message should show the bus error counts in data[7,8]:
http://lxr.free-electrons.com/source/drivers/net/can/sja1000/sja1000.c#L408
I can add this in v4 version of the patch (Above log has this patch
applied).
And please check bus-off as well (short-circuiting CAN low and high).
I have not been able to check the bus-off condition by (short-circuiting
CAN low and high). The tec error count remains at 128 when I short the
CAN low and high pins and the status never goes BUSOFF.