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 X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3AA18C2D0DB for ; Mon, 27 Jan 2020 19:08:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 08EE72467F for ; Mon, 27 Jan 2020 19:08:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Rr8cruib" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725908AbgA0TIU (ORCPT ); Mon, 27 Jan 2020 14:08:20 -0500 Received: from mail-io1-f51.google.com ([209.85.166.51]:45102 "EHLO mail-io1-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725845AbgA0TIU (ORCPT ); Mon, 27 Jan 2020 14:08:20 -0500 Received: by mail-io1-f51.google.com with SMTP id i11so11257782ioi.12 for ; Mon, 27 Jan 2020 11:08:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=/coirZNFLMH3GtP/lzxIUC8GZEKD/xRaPKrnzgmDFp4=; b=Rr8cruibHtnfakT2zM0gUBx51VaPWUB1VCXrcxuL19ncUNTnwq1a61yGHJcX4Vcmou 6smgK5teUhRz4i6LkAVpW8g6Yhg0frOyB7E5xb7jIM/pkQaVUwWe67Imkrtqq32rh1ES eJWBKq4JGAOSaqoYX3KXhEqJ9c6tlt7CEX9ls82hswNTXF0L95/XrJK/iM5FiLbJmANU i96u9M571FcjyWTaDcyq7LaJiet2Fzl9aN5q7w/aO6Xzd6XHZwqTLcxMbtYEmMtIAgty c32wpv/cX9B5lE/HfUhwhMVLuvrcMeY+2LcTENpDhk7TJ/MUS+FvPKi+3+HPSjiqOZV3 5sCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=/coirZNFLMH3GtP/lzxIUC8GZEKD/xRaPKrnzgmDFp4=; b=efSRE70u2cbiAWSqP5tJYSsXZ2IpAGn/4ba+iJbFyOVbXknuMmlvh0yu0WOuJUVJlv mf/48MCTfv7AmmQgJlUHagzsGn0Glo8wJXwJpgcwALUKQSiF2wPo/WgRqGMNzRDReLfX AGo+1G80Xnt3N/bKOY0iEYJSFDCoVLQi0LaOwjO90OX6WcPHibpIM1bnGJcTfji6BT03 FqRyXU6ip3k/puNmMsXP4d8m5qszmmdAvOsiL/v41Anzcb+/UaD01PXWZc/nkaa+0a6J RXdnyT8Ux8kNJEDzkCbgcJ2OqkGq+n8skWstlogoZ1uFJ8H9Tqo/GH4PoxKtASrq9aC7 SrOg== X-Gm-Message-State: APjAAAWllC6GUzDnIn58sVQ7OZC5TF7T4NLHg8rsrqtd82Ukf+l+rDSD hOUnaaIzLvTwy6j5e/Iu+pDFXvNbIXwWd8X3BN9WUJJBvz0= X-Google-Smtp-Source: APXvYqzNnhBmVvXFpmJC7HPExmdDdfWmIZFa7Q2THkuMjPiBvyz7MzJznRNTvIlHiU86EszoLTNh5+OqhAa74EVHaPg= X-Received: by 2002:a5d:8782:: with SMTP id f2mr13508936ion.53.1580152099313; Mon, 27 Jan 2020 11:08:19 -0800 (PST) MIME-Version: 1.0 Received: by 2002:ad5:5d0d:0:0:0:0:0 with HTTP; Mon, 27 Jan 2020 11:08:18 -0800 (PST) In-Reply-To: <20200127173034.hw6il2cnpvgl64py@beryllium.lan> References: <20200127173034.hw6il2cnpvgl64py@beryllium.lan> From: JH Date: Tue, 28 Jan 2020 06:08:18 +1100 Message-ID: Subject: Re: 4G LTE connection stability with USB voltage requirement To: Daniel Wagner Cc: connman , ofono , linux-usb Content-Type: text/plain; charset="UTF-8" Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Hi Daniel, Thanks for your response. On 1/28/20, Daniel Wagner wrote: > Hi JH, > > On Mon, Jan 27, 2020 at 01:26:41PM +1100, JH wrote: >> It seems to me there are subtle differences between connman / ofono >> and OpenWrt netifd, could the connman / ofono require more rigid >> stable USB voltage than OpenWrt netifd? Or could the OpenWrt netifd be >> more superior than connman / ofono in terms of 4G LTE connections? >> >> Appreciate your insight comments and advice. > > What about measuring the power drawn by the device? And while at it > also careful check the datasheets of the components if the tolerances > of the hardware components are meet. I did current measuring, running ConnMan and oFono, the power consumption was about 150mA - 260mA, running OpenWrt netifd, the power consumption was about 150mA - 200mA. I have to say, the result might not be accurate (1) if I change the voltage slightly, the power consumption would be different; (2) The maximum current consumption changes from time to time; (3) The DC power has only one output and one current meter, I cannot connect both devices running in parallel. I'll find a DC power supply with two power output and 2 current / voltage meters, and to buy another debug cable to connect both devices in parallel. > I cannot comment on netifd since I don't know anything about it. But > it could be that ConnMan and oFono together do more CPU work hence the > device drains more power. I can tell you from experience if the CPU > doesn't get enough power you see really random crashes and weird > behaviors. Check the reports on Raspberry Pi and power supplies. Good to know that experience, it does help a lot. Thank you Daniel, Kind regards, - jh