From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ssagarr Patil Subject: RE: C_CAN: can frame drops Date: Fri, 25 Jul 2014 13:52:01 +0530 Message-ID: References: ,<53D204A4.1060502@pengutronix.de> ,<53D2126C.40600@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from bay004-omc4s26.hotmail.com ([65.54.190.231]:55745 "EHLO BAY004-OMC4S26.hotmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750818AbaGYIWB convert rfc822-to-8bit (ORCPT ); Fri, 25 Jul 2014 04:22:01 -0400 In-Reply-To: <53D2126C.40600@pengutronix.de> Sender: linux-can-owner@vger.kernel.org List-ID: To: Marc Kleine-Budde , "linux-can@vger.kernel.org" Hi Marc, > > On 07/25/2014 10:13 AM, Ssagarr Patil wrote: >>>> 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)' >>> >>> These are the CAN frames dropped by the socket, this means as Oliver >>> pointed out, that the candump fails to read the CAN frames fast enough >>> from the socket. How do you connect to the linux box with the c_can? >>> Where are the CAN frames printed to? >>> >> Agreed this is dropped by the socket, so for this to solve I increased the socket size >> (with -r option of candump to 111173056) after doing this I see that there is frame drop in >> the driver ie I see this function c_can_handle_lost_msg_obj() being called frequently in which >> can frame is overwritten. >> >> I have a can frame generator which I have connected to the EVM, the EVM is recieving the >> frames and just dumping it on stdout going ahead I need to log the canframes to SD card. > > ...and where is your stdout going? serial line, telnet, ssh? > Its the serial line. Regards, --Sagar