Messages in this thread | | | Date | Mon, 22 Mar 2010 08:53:18 -0700 | From | "Ira W. Snyder" <> | Subject | Re: [PATCH 2/3] can: add support for Janz VMOD-ICAN3 Intelligent CAN module |
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On Sat, Mar 20, 2010 at 08:55:16AM +0100, Wolfgang Grandegger wrote: > Ira W. Snyder wrote: > > On Fri, Mar 19, 2010 at 09:13:37PM +0100, Wolfgang Grandegger wrote: > >> Ira W. Snyder wrote: > >>> On Fri, Mar 19, 2010 at 04:45:09PM +0100, Wolfgang Grandegger wrote: > >>>> Ira W. Snyder wrote: > >>>>> On Fri, Mar 19, 2010 at 10:01:14AM +0100, Wolfgang Grandegger wrote: > >>>>>> Hi Ira, > >>>>>> > >>>>>> we already discussed this patch on the SocketCAN mailing list and there > >>>>>> are just a few minor issues and the request to add support for the new > >>>>>> "berr-reporting" option, if feasible. See: > >>>>>> > >>>>>> commit 52c793f24054f5dc30d228e37e0e19cc8313f086 > >>>>>> Author: Wolfgang Grandegger <wg@grandegger.com> > >>>>>> Date: Mon Feb 22 22:21:17 2010 +0000 > >>>>>> > >>>>>> can: netlink support for bus-error reporting and counters > >>>>>> > >>>>>> This patch makes the bus-error reporting configurable and allows to > >>>>>> retrieve the CAN TX and RX bus error counters via netlink interface. > >>>>>> I have added support for the SJA1000. The TX and RX bus error counters > >>>>>> are also copied to the data fields 6..7 of error messages when state > >>>>>> changes are reported. > >>>>>> > >>>>>> Should not be a big deal. > >>>>>> > >>>>> I think this patch came along since my last post of the driver. I must > >>>>> have missed it. I'll try and add support. > >>>> No problem, it's really new. Just just need to enable BEI depending on > >>>> CAN_CTRLMODE_BERR_REPORTING. > >>>> > >>> I have one final question about this. > >>> > >>> The documentation for the firmware isn't very specific here. I believe > >>> that in order to get any kind of error messages, I need the bus error > >>> feature turned on. What is the expected behavior of an SJA1000 with the > >>> BEI (bus error interrupt) turned off? Will you still get warning > >>> messages for ERROR_ACTIVE -> ERROR_PASSIVE state transitions? > >> Yes. State transitions are enabled with EI and EPI. > >> > > > > I cannot set the registers directly, but I think I got it right. See > > below. > > > >>> I'm not sure how I would go about testing this feature, either. Ideas? > >> Send messages without cable connected and watch the error messages with > >> "candump any,0:0,#ffffffff". With "ip ... berr-reporting on" you should > >> see additional bus-errors. > >> > > > > Ok, I tried this. On one controller, I turned on bus-error reporting. On > > the other, I turn off bus-error reporting. I then tried sending lots of > > messages with the cable unplugged. Here is what happened: > > > > bus-error reporting on: > > Lots of CAN_ERR_BUSERR messages are flooded in candump. There is also a > > CAN_ERR_CRTL_TX_WARNING message, when there are too many TX errors. > > OK, you will now also understand why bus-error reporting is off by > default. On low-end systems bus-error flooding may even hang the system. > > > bus-error reporting off: > > There was only one message reported before the controller went into > > ERROR-WARNING state. It was the same CAN_ERR_CRTL_TX_WARNING message as > > above. There was no flooding of CAN_ERR_BUSERR messages. > > > > Does this seem right? It seems pretty good to me. > > Yes, I'm just missing an error-passive message. What state does "ip -d > link show can0" report. >
Ok, here is what I did:
$ ip link set can0 up type can bitrate 1000000 $ ip link set can1 up type can bitrate 1000000 berr-reporting on $ ip -d -s link 5: 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 1000000 sample-point 0.750 tq 125 prop-seg 2 phase-seg1 3 phase-seg2 2 sjw 1 janz-ican3: 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 0 0 0 RX: bytes packets errors dropped overrun mcast 0 0 0 0 0 0 TX: bytes packets errors dropped carrier collsns 0 0 0 0 0 0 6: can1: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN qlen 10 link/can can <BERR-REPORTING> state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0 bitrate 1000000 sample-point 0.750 tq 125 prop-seg 2 phase-seg1 3 phase-seg2 2 sjw 1 janz-ican3: 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 0 0 0 RX: bytes packets errors dropped overrun mcast 0 0 0 0 0 0 TX: bytes packets errors dropped carrier collsns 0 0 0 0 0 0
Now, in seperate windows, I ran cansequence and candump. I stopped cansequence when it could not send any more packets (due to the cable being unplugged).
$ cansequence -v -e -p can0 $ cansequence -v -e -p can1 $ candump any,0~0,#FFFFFFFF can0 20000004 [8] 00 08 00 00 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000004 [8] 00 08 00 00 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME can1 20000088 [8] 00 00 80 19 00 00 00 00 ERRORFRAME
This last message is repeated lots more times. That's the flooding we're avoiding with berr-reporting off.
I see two types of messages here: 1) bus error (only on can1) 2) controller problems -- tx warning limit reached (both)
Am I missing some message? My error frame generation was mostly copied from the sja1000 driver.
$ ip -d -s link 5: 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 0) restart-ms 0 bitrate 1000000 sample-point 0.750 tq 125 prop-seg 2 phase-seg1 3 phase-seg2 2 sjw 1 janz-ican3: 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 16 0 2 0 0 0 TX: bytes packets errors dropped carrier collsns 513 513 0 0 0 0 6: can1: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN qlen 10 link/can can <BERR-REPORTING> state ERROR-WARNING (berr-counter tx 128 rx 0) restart-ms 0 bitrate 1000000 sample-point 0.750 tq 125 prop-seg 2 phase-seg1 3 phase-seg2 2 sjw 1 janz-ican3: 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 0 126 0 1 0 0 RX: bytes packets errors dropped overrun mcast 1024 0 254 0 0 0 TX: bytes packets errors dropped carrier collsns 513 513 0 0 0 0
> >>> I also noticed that I can enable "self test mode" and "listen only mode" > >>> using the same firmware command. It appears that there are netlink > >>> messages for this as well. Should I try and support these, too? I don't > >>> really have any use for them (yet). I assume "self test mode" is > >>> equivalent to "loopback mode" in the netlink messages. > >> List-only is straight forward while "self test mode" is not exactly like > >> "loopback mode", IIRC. Feel free to send a follow-up patch when you have > >> time for a thorough implementation and testing. It's also on my to-do > >> list for the SJA1000. > >> > > > > Ok, then I'll put this off for a while. Feel free to pester me about it > > when there is a working implementation in the SJA1000 driver for me to > > borrow from. :) > > I will let you know when I have something working. >
Thanks, Ira
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