Re: pch_can: Data transmission stops after dropped packet

[Michael Pellegrini <mikep86@gmail.com>]

Michael Pellegrini <mikep86 <at> gmail.com> writes:

> My application has been running strong for about 45 minutes and counting with
> this driver.  I will leave the system running over Thanksgiving as a long-term
> test.

The driver has unfortunately failed the long-term test.  When I checked the
PCH-System this morning, it had hit the transmission problem again.  Dmesg 
output is:

[234700.232657] c_can_isr: irqstatus=0x6
[234700.232712] c_can_isr: irqstatus=0x6
[234700.232765] c_can_isr: irqstatus=0x6
[234700.232818] c_can_isr: irqstatus=0x6
[234700.232873] c_can_isr: irqstatus=0x6
[234700.232928] c_can_isr: irqstatus=0x6
[234700.232985] c_can_isr: irqstatus=0x6
[234700.233041] c_can_isr: irqstatus=0x6
[234700.233096] c_can_isr: irqstatus=0x6
[234700.233151] c_can_isr: irqstatus=0x6
[234700.233203] c_can_isr: irqstatus=0x6
[234700.233257] c_can_isr: irqstatus=0x6
[234700.233312] c_can_isr: irqstatus=0x6
[234700.233369] c_can_isr: irqstatus=0x6
[234700.233424] c_can_isr: irqstatus=0x6
[234700.233478] c_can_isr: irqstatus=0x6

"ip -d -s link show can0" output is:

8: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN qlen 10
    link/can
    can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0
    bitrate 250000 sample-point 0.875
    tq 500 prop-seg 3 phase-seg1 3 phase-seg2 1 sjw 1
    c_can: tseg1 2..16 tseg2 1..8 sjw 1..4 brp 1..1024 brp-inc 1
    clock 50000000
    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
    102603     43967    0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    4487315    1082899  0       0       0       0

I tried sending a message with "cansend can0 123#abcdef" and got the error 
message "write: No buffer space available".

Additionally, data reception is broken.  I can confirm via the CAN Monitor
system that the External Node system is sending messages which the PCH-System
should be receiving.  However, the RX count is not increasing and 
"candump any,0:0,#FFFFFFFF" does not show any messages being transmitted or
received on the interface.

Resetting the interface fixes data transmission and reception.  After the reset,
"ip -d -s link show can0" output is:

8: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN qlen 10
    link/can
    can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0
    bitrate 250000 sample-point 0.875
    tq 500 prop-seg 3 phase-seg1 3 phase-seg2 1 sjw 1
    c_can: tseg1 2..16 tseg2 1..8 sjw 1..4 brp 1..1024 brp-inc 1
    clock 50000000
    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
    103148     44200    0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    4487318    1082900  0       13      0       0

After the reset, dmesg output is:

[235689.911732] c_can_isr: irqstatus=0x7
[235690.358052] c_can_isr: irqstatus=0x8000
[235690.358111] c_can_isr: irqstatus=0x8
[235690.358282] c_can_isr: irqstatus=0x9
[235690.975410] c_can_isr: irqstatus=0x8000
[235690.975466] c_can_isr: irqstatus=0x1
[235691.420692] c_can_isr: irqstatus=0x8000
[235691.420749] c_can_isr: irqstatus=0x2
[235691.420899] c_can_isr: irqstatus=0x8000
[235691.420937] c_can_isr: irqstatus=0x3
[235692.038095] c_can_isr: irqstatus=0x8000
[235692.038151] c_can_isr: irqstatus=0x4
[235692.483325] c_can_isr: irqstatus=0x8000
[235692.483381] c_can_isr: irqstatus=0x5
[235692.483548] c_can_isr: irqstatus=0x8000
[235692.483587] c_can_isr: irqstatus=0x6
[235693.100729] c_can_isr: irqstatus=0x8000
[235693.100785] c_can_isr: irqstatus=0x7
[235693.545970] c_can_isr: irqstatus=0x8000
[235693.546027] c_can_isr: irqstatus=0x8
[235693.546195] c_can_isr: irqstatus=0x9

- Mike