From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ssagarr Patil Subject: RE: C_CAN: can frame drops Date: Wed, 23 Jul 2014 22:03:11 +0530 Message-ID: References: ,<53CFDD24.3070004@hartkopp.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from bay004-omc3s21.hotmail.com ([65.54.190.159]:59314 "EHLO BAY004-OMC3S21.hotmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757430AbaGWQdM convert rfc822-to-8bit (ORCPT ); Wed, 23 Jul 2014 12:33:12 -0400 In-Reply-To: <53CFDD24.3070004@hartkopp.net> Sender: linux-can-owner@vger.kernel.org List-ID: To: Oliver Hartkopp , "linux-can@vger.kernel.org" Hi Oliver, Thanks for your response :-) > > generally dropping CAN frames on driver level is a complete different problem > in opposite to dropping CAN frames on socket receive level. > Agreed. > A drop on the socket layer usually occurs, when the application does not get > enough CPU time to read and process the CAN frames. But drops on CAN driver > layer lead to a possible resource problem on your system. > For the application layer I have used chrt so that it gets higher priority. > Can you tell a bit more about your platform (hardware, CPU, cpu clock, RAM) > and Linux Kernel version? > The Linux version is 2.6.37 where as I have patched this kernel to use the v3.15 C_CAN driver(which uses D_CAN) to use. Hardware is DM8148 EVM, ARM clock is @1000Mhz, DDR @533Mhz, Regards, --Sagar > Regards, > Oliver > > > On 23.07.2014 16:48, Ssagarr Patil wrote: >> Hi, >> >> I am using the c_can driver for latest kernel and using the latest canutils to dump to a file. >> My can bus is set at a rate of 1Mb (receiving 7000fps bus load of 80%). >> >> When I use the candump tool to dump can frames I get following message, >> >> 'DROPCOUNT: dropped 2223 CAN frames on 'any' socket (total drops 1629092)' >> >> SO to solve this problem if I use the -r option of candump and tried >> candump any -d -e -r 999999999 -l >> >> If I do this the can frames are dropped in the driver ie I see >> this c_can_handle_lost_msg_obj() function being called frequently in which can frame >> is overwritten. >> >> How to solve this issue any pointers would be helpful. >> >> Thanks, >> --Sagar >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-can" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-can" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html