From: Wolfgang Grandegger <wg-5Yr1BZd7O62+XT7JhA+gdA@public•gmane.org>
To: "Ira W. Snyder" <iws-lulEs6mt1IksTUYHLfqkUA@public•gmane.org>
Cc: socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public•gmane.org,
netdev-u79uwXL29TY76Z2rM5mHXA@public•gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public•gmane.org,
sameo-VuQAYsv1563Yd54FQh9/CA@public•gmane.org
Subject: Re: [PATCH 2/3] can: add support for Janz VMOD-ICAN3 Intelligent CAN module
Date: Sat, 20 Mar 2010 08:55:16 +0100 [thread overview]
Message-ID: <4BA47F64.8030108@grandegger.com> (raw)
In-Reply-To: <20100319215227.GF13672-lulEs6mt1IksTUYHLfqkUA@public.gmane.org>
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-5Yr1BZd7O62+XT7JhA+gdA@public•gmane.org>
>>>>>> 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.
>>> 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.
Wolfgang.
next prev parent reply other threads:[~2010-03-20 7:55 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-18 16:38 [PATCH 2/3] can: add support for Janz VMOD-ICAN3 Intelligent CAN module Ira W. Snyder
[not found] ` <1268930324-29841-3-git-send-email-iws-lulEs6mt1IksTUYHLfqkUA@public.gmane.org>
2010-03-19 9:01 ` Wolfgang Grandegger
[not found] ` <4BA33D5A.8070000-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
2010-03-19 15:19 ` Ira W. Snyder
2010-03-19 15:45 ` Wolfgang Grandegger
2010-03-19 20:03 ` Ira W. Snyder
[not found] ` <20100319200325.GE13672-lulEs6mt1IksTUYHLfqkUA@public.gmane.org>
2010-03-19 20:13 ` Wolfgang Grandegger
2010-03-19 21:52 ` Ira W. Snyder
[not found] ` <20100319215227.GF13672-lulEs6mt1IksTUYHLfqkUA@public.gmane.org>
2010-03-20 7:55 ` Wolfgang Grandegger [this message]
[not found] ` <4BA47F64.8030108-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
2010-03-22 15:53 ` Ira W. Snyder
[not found] ` <20100322155318.GA19251-lulEs6mt1IksTUYHLfqkUA@public.gmane.org>
2010-03-22 19:17 ` Wolfgang Grandegger
[not found] ` <4BA7C236.9060609-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
2010-03-22 19:23 ` Wolfgang Grandegger
[not found] ` <4BA7C3BE.8040306-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
2010-03-22 20:12 ` Ira W. Snyder
2010-03-22 20:10 ` Ira W. Snyder
[not found] ` <20100322201039.GA19327-lulEs6mt1IksTUYHLfqkUA@public.gmane.org>
2010-03-22 20:28 ` Wolfgang Grandegger
[not found] ` <4BA7D2E9.6010007-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
2010-03-22 20:51 ` Ira W. Snyder
[not found] ` <20100322205101.GC19327-lulEs6mt1IksTUYHLfqkUA@public.gmane.org>
2010-03-22 21:24 ` Wolfgang Grandegger
-- strict thread matches above, loose matches on Subject: below --
2010-03-29 16:58 Ira W. Snyder
[not found] ` <1269881932-3803-3-git-send-email-iws-lulEs6mt1IksTUYHLfqkUA@public.gmane.org>
2010-03-30 8:14 ` Wolfgang Grandegger
2010-03-31 6:46 ` David Miller
2010-04-01 20:03 ` Andrew Morton
[not found] ` <20100401130359.9a9b5c7b.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
2010-04-02 0:43 ` Ira W. Snyder
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