On 08/04/2014 03:43 PM, Stefan Agner wrote:
[...]

quoted

Thanks for the test, so far looks promising :) With this setup the other
CAN node repeats the CAN frame until it's ACKed. Because there is no
node with a compatible bitrate, there is no ACking CAN node.

Can you add a third CAN node to the network. The second and third node
should use the same bitrate, while your vf610 uses a different one. With
the new setup it should take more than one frame until the vf610 goes
into error warning and even more frames to error passive. This way we
can see it the error warning interrupt is connected or not. The error
counters should increase with each "wrong" bitrate frame it sees, you
can check with:

    ip -details link show can0

The output looks like this:

quoted

4: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN mode DEFAULT qlen 10
    link/can
    can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0

                              ^^^^^^^^^^^^^^^^^^^^^^

quoted

    bitrate 1000000 sample-point 0.750
    tq 125 prop-seg 2 phase-seg1 3 phase-seg2 2 sjw 1
    sja1000: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1
    clock 8000000

When one of the berr-counter crosses 96 (and stays below 128) a warning
interrupt should be generated.

Ok, created this setup, could successfully communicate with all three
nodes. I then set the Vybrid to half of the bitrate. When I send a frame
from Vybrid, the berr-counter tx immediately ends up at 128 and the
device is in ERROR-PASSIVE:

This is expected.

root at colibri-vf:~# ip -details link show can1
3: can1: <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 0 rx 0) restart-ms 0 
    bitrate 124990 sample-point 0.739 
    tq 347 prop-seg 8 phase-seg1 8 phase-seg2 6 sjw 1
    flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1
    clock 83368421

            ^^^^^^^^

BTW: the can core has a really weird clock rate, have a look at the
datasheet if you manage to route a 24 MHz clock (or another multiple of
8MHz) to the flexcan core. I had a quick glance at the datasheet, if I
understand it correctly the Fast OSC clock runs with 24 MHz.

root at colibri-vf:~# cansend can1 1F334455#1122334455667788
interface = can1, family = 29, type = 3, proto = 1
root at colibri-vf:~# [  818.886664] flexcan_irq, esr=00062242
[  818.890365] flexcan_irq, ctrl=1c3dac57

root at colibri-vf:~# ip -details link show can1
3: can1: <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-PASSIVE (berr-counter tx 128 rx 0) restart-ms 0 
    bitrate 124990 sample-point 0.739 
    tq 347 prop-seg 8 phase-seg1 8 phase-seg2 6 sjw 1
    flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1
    clock 83368421


When I send the frames from another device on the bus, I can see the rx
count incrementing by one on each frame I send. As you expected, the
device changes to ERROR-WARNING when crossing the 96 frame boundary:

This is correct

root at colibri-vf:~# ip -details link show can1
3: can1: <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 0 rx 92) restart-ms 0 
    bitrate 124990 sample-point 0.739 
    tq 347 prop-seg 8 phase-seg1 8 phase-seg2 6 sjw 1
    flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1
    clock 83368421
root at colibri-vf:~# [  448.331150] flexcan_irq, esr=0005050a
[  448.334851] flexcan_irq, ctrl=1c3dac57
ip -details link show can1
3: can1: <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-WARNING (berr-counter tx 0 rx 102) restart-ms 0 
    bitrate 124990 sample-point 0.739 
    tq 347 prop-seg 8 phase-seg1 8 phase-seg2 6 sjw 1
    flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1
    clock 83368421

However, once reaching 128, I don't get another interrupt and the device
stays in ERROR-WARNING:

The contents of the esr reg would be interesting, especially the
FLT_CONF part.

3: can1: <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-WARNING (berr-counter tx 0 rx 128) restart-ms 0 
    bitrate 124990 sample-point 0.739 
    tq 347 prop-seg 8 phase-seg1 8 phase-seg2 6 sjw 1
    flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1
    clock 83368421

Is this the expected behavior on receive?

No, it should go into error passive if one of the error counters have >
127. Maybe this is an error onthe vf610, maybe it's a general flexcan
problem.

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
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