From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C80AAC43219 for ; Thu, 24 Nov 2022 20:15:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229555AbiKXUPb (ORCPT ); Thu, 24 Nov 2022 15:15:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42454 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229448AbiKXUPa (ORCPT ); Thu, 24 Nov 2022 15:15:30 -0500 Received: from mo4-p00-ob.smtp.rzone.de (mo4-p00-ob.smtp.rzone.de [85.215.255.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A94A6B0400 for ; Thu, 24 Nov 2022 12:15:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1669320927; s=strato-dkim-0002; d=hartkopp.net; h=In-Reply-To:From:References:Cc:To:Subject:Date:Message-ID:Cc:Date: From:Subject:Sender; bh=3ygsWgrhXXE8axZOoLemAejOIr47WU1+gNB4+7gimYY=; b=UH9opzLkV4rsQzwLivM0xJneJOPoeNOVqgHJcdlDEEdLrH44u+aykw1Wh1EDTF335j iZEaIMKoW7KDvP0+UCwDDhsxqwzj/I8+mT2hI+Hm3sDXmH9jSVTHJ2zBWj3sj94T50Dj GQ/YEMsGU7JGu3CX1Iju+ihu5dlLzLwEoxtzotp71IGxpxXydgz1xJ/7C6utnFjIiXW6 4jRGiTcyOqJvMzR8zqb/o+CxIX8aK/l8I+4vDE+0k9012XECeZ+Uebx+Avv3JLVgDGOM k0wsk1j8G5fg0IufBSGanfbFuk6JbyGhzP6V3xq93zr0TnwE5lKPEjxPVjYqzJiiWl3D lwnA== Authentication-Results: strato.com; dkim=none X-RZG-AUTH: ":P2MHfkW8eP4Mre39l357AZT/I7AY/7nT2yrDxb8mjG14FZxedJy6qgO1qCHSa1GLptZHusx3hdIrpKytISr6hZqJAw==" X-RZG-CLASS-ID: mo00 Received: from [IPV6:2a00:6020:1cfd:d104::923] by smtp.strato.de (RZmta 48.2.1 AUTH) with ESMTPSA id Dde783yAOKFRJCW (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Thu, 24 Nov 2022 21:15:27 +0100 (CET) Message-ID: <70b9e4a0-69ed-ba6a-ac3a-4e20aa9fc251@hartkopp.net> Date: Thu, 24 Nov 2022 21:15:21 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: [PATCH] can: mcba_usb: Fix termination command argument To: Yasushi SHOJI Cc: Marc Kleine-Budde , =?UTF-8?B?UmVtaWdpdXN6IEtvxYLFgsSFdGFq?= , Yasushi SHOJI , Wolfgang Grandegger , linux-can@vger.kernel.org References: <20221123194406.80575-1-yashi@spacecubics.com> <20221123223410.sg2ixkaqg4dpe7ew@pengutronix.de> <5a309931-ca81-5433-b437-5c8ec23c4d85@hartkopp.net> Content-Language: en-US From: Oliver Hartkopp In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org Hi Yashi, On 24.11.22 14:13, Yasushi SHOJI wrote: > I've checked with one of my colleagues and he told me I measured it wrong. Ok. > Here is a correction. > > You can find the schematic of the analyzer in its user's guide > https://www.microchip.com/en-us/development-tool/APGDT002 > or directly at https://ww1.microchip.com/downloads/aemDocuments/documents/APG/ProductDocuments/UserGuides/CAN-Bus-Analyzer-Users-Guide-DS50001848C.pdf > > The schematics is at page 11. > > Basically the "termination" controls the CAN_RES signal. When it's > low, R24 and R25 are connected to the bus. > They are 56 Ohms. Ah, that means 2 x 56 Ohms => 112 Ohms (nearly 120) > With my patch, "termination 120" drives CAN_RES low and the resistors > are active, and "termination 0" drives it high. Thanks for the clarification! Best regards, Oliver