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From: Oliver Hartkopp <socketcan@hartkopp.net>
To: Marc Kleine-Budde <mkl@pengutronix.de>,
	wouter van herpen <wouter.van.herpen@prodrive-technologies.com>,
	linux-can@vger.kernel.org
Subject: Re: c_can: wrong frame order reception
Date: Thu, 22 Oct 2015 07:05:35 +0200	[thread overview]
Message-ID: <56286E9F.7040909@hartkopp.net> (raw)
In-Reply-To: <5627A245.50401@pengutronix.de>

Hi Wouter,

On 21.10.2015 16:33, Marc Kleine-Budde wrote:
> On 10/21/2015 11:19 AM, wouter van herpen wrote:
>> I am currently working on the Intel atom platform with EG20T.
>>
>> Using the c_can driver from the main line 4.1.10 kernel sources, I still see
>> frames received in a swapped order.
>>
>> It looks like all the patches mentioned in the list above are already
>> applied in this main line c_can driver.
>>
>> Is the frame order swapping still a known issue? Are there any additional
>> patches regarding this issue that I'm not aware off?
>
> Maybe Oliver can help. What's needed on a v4.1.10 SMP system to fix the
> RX order?
>

you can try to use the SMP-affinity to pin the innterrupt to a specific CPU:

	https://www.kernel.org/doc/Documentation/IRQ-affinity.txt

But we're currently also checking the usability of receive packet steering 
(RPS) on SMP systems. Please check

	http://marc.info/?l=linux-can&m=144251788500555&w=2

whether just using

	echo f > /sys/class/net/can0/queues/rx-0/rps_cpus

helps in you case or whether you need to set the skb hash which is suggested 
there too.

Best regards,
Oliver

  reply	other threads:[~2015-10-22  5:05 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-05 14:58 c_can: wrong frame order reception Alexander Stein
2014-03-05 15:13 ` Alexander Stein
2014-04-01 18:33   ` Oliver Hartkopp
2014-04-02  5:57     ` Alexander Stein
2014-04-03 13:41     ` Alexander Stein
2014-04-03 14:01       ` Wolfgang Grandegger
2015-10-21  9:19         ` wouter van herpen
2015-10-21 14:12           ` Marc Kleine-Budde
2015-10-21 14:28             ` wouter van herpen
2015-10-21 14:33           ` Marc Kleine-Budde
2015-10-22  5:05             ` Oliver Hartkopp [this message]
2015-10-22  9:50               ` wouter van herpen
2015-10-22 17:01                 ` Oliver Hartkopp

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