From: Stanislav Meduna <stano@meduna.org>
To: linux-can@vger.kernel.org
Cc: wg@grandegger.com, Marc Kleine-Budde <mkl@pengutronix.de>
Subject: FlexCAN i.MX28 BUG! hardware recovered automatically from BUS_OFF
Date: Wed, 16 Apr 2014 13:52:43 +0200 [thread overview]
Message-ID: <534E6F0B.70100@meduna.org> (raw)
On 07.03.2014 09:08, Stanislav Meduna wrote:
Hi,
I am using a FlexCAN CAN controller on a Freescale i.MX28
platform [1] and I am upgrading from kernel 3.4 to 3.12.15-rt25.
I am testing the behaviour regarding bus errors, so I run
a test program where the can1 sends and can0 receives and
I am trying to induce bus problems.
If there is no ip link set ... restart-ms parametrized,
the bus does not recover from being left unconnected for
a while
# ip -d -s link show can1
3: can1: <NO-CARRIER,NOARP,UP,ECHO> mtu 16 qdisc pfifo_fast state DOWN qlen 10
link/can
can state BUS-OFF (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
flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1
clock 24000000
re-started bus-errors arbit-lost error-warn error-pass bus-off
0 0 0 7 3 2
RX: bytes packets errors dropped overrun mcast
320 130 0 0 0 0
TX: bytes packets errors dropped carrier collsns
117 59 0 1 0 0
If I configure restart-ms 100, the controller recovers
3: can1: <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 100
bitrate 500000 sample-point 0.875
tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
flexcan: tseg1 4..16 tseg2 2..8 sjw 1..4 brp 1..256 brp-inc 1
clock 24000000
re-started bus-errors arbit-lost error-warn error-pass bus-off
20 0 0 27 23 22
RX: bytes packets errors dropped overrun mcast
960 210 0 0 0 0
TX: bytes packets errors dropped carrier collsns
147 73 0 22 0 0
but while disconnected it floods the log with
[ 1866.452038] flexcan 80034000.can can1: writing ctrl=0x0231a055
[ 1867.447723] flexcan 80034000.can can1: BUG! hardware recovered automatically from BUS_OFF
[ 1867.456128] flexcan 80034000.can can1: writing ctrl=0x0231a055
[ 1868.447649] flexcan 80034000.can can1: BUG! hardware recovered automatically from BUS_OFF
Is this the expected behaviour? What exactly is the "BUG"?
Please Cc: me when replying.
[1] http://www.tq-group.com/en/products/product-details/prod/embedded-modul-tqma28/extb/Main/productdetail/
Thanks
--
Stano
reply other threads:[~2014-04-16 11:52 UTC|newest]
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