The message rate is low (about 25 frames/s). I've stopped all periodic
frames and just sent single frames manually (from the Kvaser software) and I
still get the same error frame after each [correct] reception.
Here's the output of that command:
root:/> ip -d -s link show can0
2: can0: <NOARP,UP,LOWER_UP,40000> mtu 16 qdisc pfifo_fast state UNKNOWN
qlen 10
link/[280]
can state STOPPED restart-ms 0
bitrate 500000 sample-point 0.800
tq 400 prop-seg 1 phase-seg1 2 phase-seg2 1 sjw 1
bfin_can: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 4..1024 brp-inc 1
clock 125000000
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
20342390 2565939 1282969 0 1282969 0
TX: bytes packets errors dropped carrier collsns
0 0 0 0 0 0
root:/>
Hopefully Barry has some insight.
- Jay
On Fri, Feb 18, 2011 at 1:50 PM, Wolfgang Grandegger <[email protected]>wrote:
> On 02/18/2011 07:58 PM, Joseph Kubicky wrote:
> > I'm using socketcan on a custom Analog Devices BF537 board running
> uClinux.
> > I'm using ADI's 2010R1 uClinux (2.6.34.7-ADI-2010R1-pre-svn9156), but I
> > don't know how to find out what version of the socketcan driver is in
> there
>
> The bfin_can Socket-CAN driver is mainline since 2.6.33 but I can't tell
> if it uses it.
>
> > (if someone could tell me I'd appreciate it). I'm using the BF537's
> > built-in CAN controller. My application is receiving all the CAN frames
> I
> > expect, but ifconfig is telling me that fully 1/2 of the packets being
> > received are error frames. I also have a Kvaser CAN analyzer on my bus
> and
> > it isn't reporting any errors at all. My packet rate is pretty low -
> around
> > 25 frames/s on a 500Kbit bus.
> >
> > Exploring a little more, if I look at the bus transcript from my CAN
> > analyzer I see something like:
> >
> > 0 00000020 8 1B 00 07 98 80 09 88 80 515.903420 R
> > 0 00000020 8 1B 08 0B 78 80 09 78 80 515.903610 R
> > 0 00000020 8 1B 10 07 88 80 08 78 80 515.903870 R
> > 0 00000020 8 1B 14 07 C8 81 07 58 80 515.904120 R
> > 0 00000020 8 1B 04 0B 98 80 08 88 80 515.904380 R
> > 0 00000020 8 1B 0C 07 98 80 09 58 80 515.904570 R
> > 0 00000060 6 6B 2B 00 00 00 00 515.911100 R
> > 0 00000020 8 1F 00 08 98 80 09 88 80 516.153400 R
> > 0 00000020 8 1F 08 0B 78 80 09 78 80 516.153660 R
> > 0 00000020 8 1F 10 07 78 80 08 78 80 516.153910 R
> > 0 00000020 8 1F 14 07 D8 81 07 58 80 516.154170 R
> > 0 00000020 8 1F 04 0A 98 80 07 88 80 516.154360 R
> > 0 00000020 8 1F 0C 07 98 80 09 68 80 516.154620 R
>
> Are you sending the messages at a very high rate?
>
> > But if I run candump can0 -m 0 -e 0xffffffff on my host I get:
>
> This seems to be a very old version of the can-utils. Anyway, that's not
> the problem. I think.
>
> > can0 20 [8] 1B 00 07 98 80 09 88 80
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
>
> This is an CAN_ERR_CRTL_RX_OVERFLOW error (from Receive Message Lost
> Interrupt Status).
>
> > can0 20 [8] 1B 08 0B 78 80 09 78 80
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
> > can0 20 [8] 1B 10 07 88 80 08 78 80
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
> > can0 20 [8] 1B 14 07 C8 81 07 58 80
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
> > can0 20 [8] 1B 04 0B 98 80 08 88 80
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
> > can0 20 [8] 1B 0C 07 98 80 09 58 80
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
> > can0 60 [6] 6B 2B 00 00 00 00
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
> > can0 20 [8] 1F 00 08 98 80 09 88 80
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
> > can0 20 [8] 1F 08 0B 78 80 09 78 80
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
> > can0 20 [8] 1F 10 07 78 80 08 78 80
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
> > can0 20 [8] 1F 14 07 D8 81 07 58 80
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
> > can0 20 [8] 1F 04 0A 98 80 07 88 80
> > can0 20000004 [8] 00 01 00 00 00 00 00 00 ERRORFRAME
> > can0 20 [8] 1F 0C 07 98 80 09 68 80
>
> But the received data seem to be correct. What does the following
> command tell you:
>
> # ip -d -s link show can0
>
> > These frames are being generated by some custom boards of mine, but I get
> > exactly the same error frame even if I generate a frame from the Kvaser.
> My
> > bus is properly terminated (at both ends) and is very short for this test
> > setup - just three nodes (+ the analyzer), separated from one another by
> > ~1ft of twisted-pair. The only configuration I do is when I start the
> > interface in /etc/rc:
> >
> > ip link set can0 type can bitrate 500000
> > ifconfig can0 up
> >
> > I assume the detailed bit timing is being set to some default values by
> the
> > driver... I wonder if that could be my problem.
>
> The errors seems not due to electrical problems.
>
> > Has anyone else seen this type of problem? Any ideas how to troubleshoot
> > it?
>
> Looks wired. Maybe the maintainer of the driver does have an idea (added
> to CC)
>
> Wolfgang.
>
>
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