From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752147Ab1BHHzV (ORCPT ); Tue, 8 Feb 2011 02:55:21 -0500 Received: from mail-out.m-online.net ([212.18.0.10]:48640 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752013Ab1BHHzU (ORCPT ); Tue, 8 Feb 2011 02:55:20 -0500 X-Auth-Info: abF9G/0zPcQWUKNHpxcVsSmyMa8tM5kNv+o0ZpyAcfI= Message-ID: <4D50F75A.5040700@grandegger.com> Date: Tue, 08 Feb 2011 08:57:14 +0100 From: Wolfgang Grandegger User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.12) Gecko/20100907 Fedora/3.0.7-1.fc12 Thunderbird/3.0.7 MIME-Version: 1.0 To: Tomoya MORINAGA CC: socketcan-core@lists.berlios.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: About bittiming calculation result References: <20110204124233.GB334@e-circ.dyndns.org> <20110204.130649.112613896.davem@davemloft.net> <5009516791F146C49C73FAC57C437313@hacdom.okisemi.com> <4D4FDEF9.2030305@grandegger.com> <4D501555.5000905@grandegger.com> <93C12206407640199DCDD3A89A333F13@hacdom.okisemi.com> In-Reply-To: <93C12206407640199DCDD3A89A333F13@hacdom.okisemi.com> X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tomoya, On 02/08/2011 02:27 AM, Tomoya MORINAGA wrote: > On Tuesday, February 08, 2011 12:53 AM, Wolfgang Grandegger wrote: > >> BTW, it's always possible to specify optimized bit-timing >> parameters directly, e.g. the following seem better: >> >> 800000 60 12 4 4 4 3 793650 0.8% 80.0% 81.0% 1.2% >> >> You could set these with: >> >> $ ip link set can0 type can \ >> tq 60 prop-seg 12 phase-seg1 4 phase-seg2 4 sjw 4 > > I can confirm 800K comms works well using the above. Cool, I got these magic values from a CAN hardware expert. > I wish Can-core could calculate like above. Me too! I also got some indication on how to improve our algorithm in case the bit-rate does not match. Hope to find some time soon to work on this issue. >>> seg1/seg2/sjw/prop_seg must be more than 1 ? > BTW, according to EG20T PCH data sheet, > CAN bit-timing parameters(BRP, Prop_Seg, Phase_Seg1, Phase_Seg2, SJW) must not be set 0. OK, then please provide a patch setting tseg1_min to 2. Wolfgang. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Grandegger Subject: Re: About bittiming calculation result Date: Tue, 08 Feb 2011 08:57:14 +0100 Message-ID: <4D50F75A.5040700@grandegger.com> References: <20110204124233.GB334@e-circ.dyndns.org> <20110204.130649.112613896.davem@davemloft.net> <5009516791F146C49C73FAC57C437313@hacdom.okisemi.com> <4D4FDEF9.2030305@grandegger.com> <4D501555.5000905@grandegger.com> <93C12206407640199DCDD3A89A333F13@hacdom.okisemi.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Tomoya MORINAGA Return-path: In-Reply-To: <93C12206407640199DCDD3A89A333F13-c0cKtqp5df7I9507bXv2FdBPR1lH4CV8@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org Errors-To: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org List-Id: netdev.vger.kernel.org Hi Tomoya, On 02/08/2011 02:27 AM, Tomoya MORINAGA wrote: > On Tuesday, February 08, 2011 12:53 AM, Wolfgang Grandegger wrote: > >> BTW, it's always possible to specify optimized bit-timing >> parameters directly, e.g. the following seem better: >> >> 800000 60 12 4 4 4 3 793650 0.8% 80.0% 81.0% 1.2% >> >> You could set these with: >> >> $ ip link set can0 type can \ >> tq 60 prop-seg 12 phase-seg1 4 phase-seg2 4 sjw 4 > > I can confirm 800K comms works well using the above. Cool, I got these magic values from a CAN hardware expert. > I wish Can-core could calculate like above. Me too! I also got some indication on how to improve our algorithm in case the bit-rate does not match. Hope to find some time soon to work on this issue. >>> seg1/seg2/sjw/prop_seg must be more than 1 ? > BTW, according to EG20T PCH data sheet, > CAN bit-timing parameters(BRP, Prop_Seg, Phase_Seg1, Phase_Seg2, SJW) must not be set 0. OK, then please provide a patch setting tseg1_min to 2. Wolfgang.