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=-8.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 76ACBC433E2 for ; Mon, 14 Sep 2020 10:00:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3312420735 for ; Mon, 14 Sep 2020 10:00:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="P3wlB8+4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726303AbgINKAU (ORCPT ); Mon, 14 Sep 2020 06:00:20 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:19664 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726239AbgINKAS (ORCPT ); Mon, 14 Sep 2020 06:00:18 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1600077617; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=RMWWi08qE+zVDjsvs5PNkxLphO7CpEmaJmcY8F/dYqE=; b=P3wlB8+4aiXkFMOpbPqiTZwR/pNDO9LdHhDLtZO7N3HZBPQIs3w88yAapa/cTromRlTHO4NO bEKGmoDzIq+xSmzOZMKDC1pTuRenVlQidPA7YlywNHchq9MrhFkAf2iQM2imp0ICyjWEmp4C /x/N5XbRRLqBLYoYWQrfnsh4KWA= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyIzZmY0MiIsICJsaW51eC1zZXJpYWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n02.prod.us-west-2.postgun.com with SMTP id 5f5f3f167f21d51b30bc8939 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 14 Sep 2020 09:59:50 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id B8173C433FF; Mon, 14 Sep 2020 09:59:49 +0000 (UTC) Received: from [192.168.43.98] (unknown [47.8.187.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: akashast) by smtp.codeaurora.org (Postfix) with ESMTPSA id 62A9DC433CA; Mon, 14 Sep 2020 09:59:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 62A9DC433CA Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=akashast@codeaurora.org Subject: Re: [PATCH] tty: serial: qcom_geni_serial: 115.2 is a better console default than 9600 To: Douglas Anderson , Greg Kroah-Hartman Cc: Nick Desaulniers , robdclark@chromium.org, Nathan Chancellor , jwerner@chromium.org, Andy Gross , Bjorn Andersson , Jiri Slaby , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org References: <20200911080054.1.I4c00b921c2f17b6988688046fa7be0f729f8d591@changeid> From: Akash Asthana Message-ID: <981cfc91-035e-57cb-5972-e2a749adae98@codeaurora.org> Date: Mon, 14 Sep 2020 15:29:25 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200911080054.1.I4c00b921c2f17b6988688046fa7be0f729f8d591@changeid> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On 9/11/2020 8:30 PM, Douglas Anderson wrote: > Commit c5cbc78acf69 ("tty: serial: qcom_geni_serial: Initialize baud > in qcom_geni_console_setup") fixed a bug by initting a variable that > was used in some cases without initialization. However, the "default" > baud rate picked by that CL was probably not the best choice. The > chances that anyone out there is trying to run a system with kernel > messages piped out over a 9600 baud serial port is just about nil. > Console messages are printed in a blocking manner. At 9600 baud we > print about 1 character per millisecond which means that printing a > 40-byte message to the console will take ~40 ms. While it would > probably work, it's going to make boot _very_ slow and probably cause > the occasional timeout here and there in drivers (heck, even at 115200 > console delays can wreck havoc). > > This has already bit at least two people that I'm aware of that tried > to enable serial console by just adding "console=ttyMSM0" (instead of > "console=ttyMSM0,115200n8") to the command line, so it seems like it'd > be nice to fix. > > Let's switch the default to 115200. Reviewed-by: Akash Asthana > Signed-off-by: Douglas Anderson > --- > > -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project