From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Hartkopp Subject: Re: c_can: wrong frame order reception Date: Thu, 22 Oct 2015 07:05:35 +0200 Message-ID: <56286E9F.7040909@hartkopp.net> References: <2323199.vffRdFDsB5@ws-stein> <7234338.9RqiOdiLOY@ws-stein> <533B067A.3030609@hartkopp.net> <1451869.V7QBi99RiY@ws-stein> <5627A245.50401@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mo4-p00-ob.smtp.rzone.de ([81.169.146.160]:30338 "EHLO mo4-p00-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751161AbbJVFFn (ORCPT ); Thu, 22 Oct 2015 01:05:43 -0400 In-Reply-To: <5627A245.50401@pengutronix.de> Sender: linux-can-owner@vger.kernel.org List-ID: To: Marc Kleine-Budde , wouter van herpen , linux-can@vger.kernel.org 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