Re: [PATCH net-next v2 2/4] can: cc770: add legacy ISA bus driver for the CC770 and AN82527

Hi Wolfgang,

On 12/11/2011 07:33 PM, Wolfgang Zarre wrote:

Hello Wolfgang,

quoted

On 12/07/2011 02:42 PM, Wolfgang Grandegger wrote:

quoted

Hi Wolfgang,

On 12/06/2011 10:08 PM, Wolfgang Zarre wrote:

...

quoted

quoted

quoted

Let me know if You need more or some other tests.

You could provoke some state changes or bus-off conditions to see if the
berr-counter shows reasonable results. I'm currently consolidating and
unifying error state and bus-off handling. Would be nice if you could do
some further tests when I have the patches ready...

I just pushed the mentioned modifications to the "devel" branch of my
"wg-linux-can-next" [1] repository. You can get it as shown below:

   $ git clone --reference=<some-recent-net-next-tree>  \
       git://gitorious.org/~wgrandegger/linux-can/wg-linux-can-next.git
   $ git checkout -b devel devel

[1] https://gitorious.org/~wgrandegger/linux-can/wg-linux-can-next

Wolfgang.

OK, I was trying so far and You will find below the results.
Just FYI the states on the PLC side couldn't be verified because the
function
provided by the manufacturer is not working at all and CAN analyser was not
available.

We are running CANopen and therefore the PLC will send automatically a
heartbeat.

I produced the bus-off state through a short circuit between L/H which was
working as expected.

A bit odd was that on the second try I had to reload the module
because a ip down/up was not enough.

Oops, not good.

Let me know if You would need further tests or different procedure.

The state changes are reported via error messages, which you can list
with "candump -td -e any,0:0,#FFFFFFFF" with the attached patch.

Producing L/H short circuit for 2 seconds
dmesg:
[  885.409058] cc770_isa cc770_isa.0: can0: status interrupt (0x5b)
[  885.420475] cc770_isa cc770_isa.0: can0: status interrupt (0xc5)
[  885.420496] cc770_isa cc770_isa.0: can0: bus-off

ip -d -s link show can0
4: can0: <NO-CARRIER,NOARP,UP,ECHO> mtu 16 qdisc pfifo_fast state DOWN
qlen 10
    link/can
    can state BUS-OFF (berr-counter tx 92 rx 103) restart-ms 0
    bitrate 500000 sample-point 0.875
    tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
    cc770: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1
    clock 8000000
    re-started bus-errors arbit-lost error-warn error-pass bus-off
    0          0          0          1          0          1
    RX: bytes  packets  errors  dropped overrun mcast
    544        382      0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    30         29       0       0       0       0

Sending and receiving stops.

Trying to recover on PC:
ip link set can0 down;
ip -d -s link show can0
4: can0: <NOARP,ECHO> mtu 16 qdisc pfifo_fast state DOWN qlen 10
    link/can
    can state STOPPED (berr-counter tx 92 rx 103) restart-ms 0
    bitrate 500000 sample-point 0.875
    tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
    cc770: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1
    clock 8000000
    re-started bus-errors arbit-lost error-warn error-pass bus-off
    0          0          0          1          0          1
    RX: bytes  packets  errors  dropped overrun mcast
    544        382      0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    30         29       0       1       0       0

ip link set can0 up type can bitrate 500000;
dmesg:
[ 1090.937778] cc770_isa cc770_isa.0: can0: setting BTR0=0x00 BTR1=0x1c
[ 1090.937869] cc770_isa cc770_isa.0: can0: Message object 15 for RX
data, RTR, SFF and EFF
[ 1090.937885] cc770_isa cc770_isa.0: can0: Message object 11 for TX
data, RTR, SFF and EFF
[ 1090.938050] ADDRCONF(NETDEV_CHANGE): can0: link becomes ready
[ 1090.940769] cc770_isa cc770_isa.0: can0: status interrupt (0x5)

ip -d -s link show can0
4: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UP qlen 10
    link/can
    can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0
    bitrate 500000 sample-point 0.875
    tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
    cc770: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1
    clock 8000000
    re-started bus-errors arbit-lost error-warn error-pass bus-off
    0          0          0          1          0          1
    RX: bytes  packets  errors  dropped overrun mcast
    552        383      0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    30         29       0       1       0       0

PLC in unknown state but not sending heartbeat,
Rebooting PLC

Hm, does it work if you do the bus-off recovery manually with?

  # ip link set can0 up type can restart

... or automatically with?

  # ip link set can0 up type can restart-ms 5000

Anyway, rebooting/reloading should never be necessary. I will check on
my i82572.

-----------------------------------------
Disconnecting cable for around 4 seconds:

dmesg:
[ 2339.660283] cc770_isa cc770_isa.0: can0: status interrupt (0x5b)

ip -d -s link show can0
6: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN
qlen 10
    link/can
    can state ERROR-WARNING (berr-counter tx 128 rx 128) restart-ms 0
    bitrate 500000 sample-point 0.875
    tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
    cc770: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1
    clock 8000000
    re-started bus-errors arbit-lost error-warn error-pass bus-off
    0          0          0          1          0          0
    RX: bytes  packets  errors  dropped overrun mcast
    459        298      0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    193        192      0       0       0       0

TX and RX berr-counter are >= 128. I wonder why error passive was not
reached.

Connecting again:
ip -d -s link show can0
6: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN
qlen 10
    link/can
    can state ERROR-WARNING (berr-counter tx 120 rx 0) restart-ms 0
    bitrate 500000 sample-point 0.875
    tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
    cc770: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1
    clock 8000000
    re-started bus-errors arbit-lost error-warn error-pass bus-off
    0          0          0          1          0          0
    RX: bytes  packets  errors  dropped overrun mcast
    473        311      0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    200        200      0       0       0       0

After some time (around 125 seconds):
dmesg:
[ 2387.172008] cc770_isa cc770_isa.0: can0: status interrupt (0x18)
ip -d -s link show can0
6: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN
qlen 10
    link/can
    can state ERROR-ACTIVE (berr-counter tx 29 rx 0) restart-ms 0
    bitrate 500000 sample-point 0.875
    tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
    cc770: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1
    clock 8000000
    re-started bus-errors arbit-lost error-warn error-pass bus-off
    0          0          0          1          0          0
    RX: bytes  packets  errors  dropped overrun mcast
    616        447      0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    291        291      0       0       0       0

OK, the state is back to error active (counter < 96).

Thanks for testing...

Wolfgang.