Linux CAN drivers development
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From: Wolfgang Grandegger <wg@grandegger.com>
To: Martin Kozusky <mkozusky@kkmicro.cz>
Cc: linux-can@vger.kernel.org
Subject: Re: CAN messages being lost on i.MX25 with flexcan
Date: Fri, 20 Apr 2012 09:59:29 +0200	[thread overview]
Message-ID: <4F911761.6040807@grandegger.com> (raw)
In-Reply-To: <jmqv1m$38p$1@dough.gmane.org>

On 04/20/2012 08:17 AM, Martin Kozusky wrote:
> Dne 20.4.2012 8:04, Wolfgang Grandegger napsal(a):
...
>> You are obviously hitting the resource limits. Do you need -rt? It makes
>> your system slower.
> 
> I don't know what steps are necessary to make the kernel (and can
> driver) -rt :(  I will first try to finish my app and see how it behaves.

Forget my comment. I was thinking that you are already using a -rt
kernel (with the real-time preemption patch), but that's obviously not
the case. Sorry for the noise.

...
>> Good. What does the CAN statistics show ($ ip -d -s link show can0)?
> 
> Now it shows (after some time of experimenting, it was disconnected from
> canbus for a while)
> 
> 2: can0: <NOARP,ECHO> mtu 16 qdisc pfifo_fast state DOWN mode DEFAULT
> qlen 10
>     link/can
>     can state STOPPED (berr-counter tx 0 rx 0) restart-ms 0
>     bitrate 250000 sample-point 0.857
>     tq 285 prop-seg 5 phase-seg1 6 phase-seg2 2 sjw 1
>     flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1
>     clock 66500000
>     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
>     4758311    602831   212     0       212     0

There have been some RX FIFO overflow errors, which means messages are
lost by the hardware.

Wolfgang.

  reply	other threads:[~2012-04-20  7:59 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-19 10:04 CAN messages being lost on i.MX25 with flexcan Martin Kozusky
2012-04-19 10:54 ` Wolfgang Grandegger
2012-04-19 11:21   ` Martin Kozusky
2012-04-19 11:44     ` Wolfgang Grandegger
2012-04-19 11:58       ` Martin Kozusky
2012-04-19 13:37         ` Wolfgang Grandegger
2012-04-20  5:51           ` Martin Kozusky
2012-04-20  6:04             ` Wolfgang Grandegger
2012-04-20  6:17               ` Martin Kozusky
2012-04-20  7:59                 ` Wolfgang Grandegger [this message]
2012-04-19 20:00         ` Jesper Pedersen
2012-04-19 20:17           ` Wolfgang Grandegger

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