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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 B6D1AC43461 for ; Fri, 11 Sep 2020 15:56:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7122721D7E for ; Fri, 11 Sep 2020 15:56:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="GmV5kJx6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726530AbgIKP4E (ORCPT ); Fri, 11 Sep 2020 11:56:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725992AbgIKPzp (ORCPT ); Fri, 11 Sep 2020 11:55:45 -0400 Received: from mail-qt1-x844.google.com (mail-qt1-x844.google.com [IPv6:2607:f8b0:4864:20::844]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15E72C061756; Fri, 11 Sep 2020 08:55:45 -0700 (PDT) Received: by mail-qt1-x844.google.com with SMTP id v54so8209686qtj.7; Fri, 11 Sep 2020 08:55:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=aV5bpQ2krhOB+niC7lEQtlN1tkAGF/USFR0HH0F56g8=; b=GmV5kJx6TnLDNUqRs4lH9VY2bK80Nm2uLz+5U1MgxZzpgZ85HnOQZjpbS7SrjbzCUa WDt3phlxcNon8OhgUWmK0czetjiyrfTeASu0u39E4aifSd56uOQvWM0+mTGkSVqVu+4a v7nLtoQGbafhhmRUb9WacVm1Q7kbaNElqsCloSYeBtCj+3Do+uLWLqJep7Gopp6Yw4nr exb8vn/RuzFrzqIAFEys/+PlRC+scyIs6kiEJKUogjknHDXN09JgEKiXL2KRbt09IA6v mgixLErw0uHL8SpcRvB4p+Ch+zNBKoSWltZ2p3+m9GAz+8etLb32TtIl3jZMF/BBxle3 Q1qg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=aV5bpQ2krhOB+niC7lEQtlN1tkAGF/USFR0HH0F56g8=; b=QgQqFengJM+90VhBs6+kZT43HCANgGjGDrBGC43NriH9aJiU6onnU7sb38HdMawsaS boCFSf3dwSvDzaNjyUm3EbOQnFSN68RTdqIWF8sYYHXe4wR6fhg2tCGYpMNiQDK8BEaZ NSgEOI0t8M61YsfeBiO9edsAnI4Y/3/l1skILQSOctn8pUSU2JV5uYTuvp5DqFmNUrYT WDuykEwI+07HFC+Z/h6oU3iAMXOSM7009pkxSHt8On2sNesWLcwNratxVb0T8wqMHLt5 qtdRkGc5mgyNbJnwCB5lpmAayPw29kXeij9GUiuhOXMYq9OKJhYSEzYTXLPPYDRWwpER m2Mw== X-Gm-Message-State: AOAM533/hVEc6fu4ke3qnQK47SKHu2xJPntGRu2VZ1DJym3ld84erJXh vw1iVsiskamq/5m0qw+LlYc= X-Google-Smtp-Source: ABdhPJzfJ7Pc2ZjSn75Qlos68p60gX+HasTYd8IiJnlbetV9wqSQzG5KIPdnxzE8SZbfXg+Jp5hXlg== X-Received: by 2002:ac8:22da:: with SMTP id g26mr2421314qta.218.1599839744238; Fri, 11 Sep 2020 08:55:44 -0700 (PDT) Received: from ubuntu-n2-xlarge-x86 ([2604:1380:45d1:2600::1]) by smtp.gmail.com with ESMTPSA id r34sm3365906qtr.18.2020.09.11.08.55.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Sep 2020 08:55:43 -0700 (PDT) Date: Fri, 11 Sep 2020 08:55:42 -0700 From: Nathan Chancellor To: Douglas Anderson Cc: Greg Kroah-Hartman , Nick Desaulniers , robdclark@chromium.org, Akash Asthana , 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 Subject: Re: [PATCH] tty: serial: qcom_geni_serial: 115.2 is a better console default than 9600 Message-ID: <20200911155542.GA4037107@ubuntu-n2-xlarge-x86> References: <20200911080054.1.I4c00b921c2f17b6988688046fa7be0f729f8d591@changeid> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200911080054.1.I4c00b921c2f17b6988688046fa7be0f729f8d591@changeid> Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On Fri, Sep 11, 2020 at 08:00:57AM -0700, 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. > > Signed-off-by: Douglas Anderson Reviewed-by: Nathan Chancellor > --- > > drivers/tty/serial/qcom_geni_serial.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c > index f0b1b47c3abc..e390ffc8bbbd 100644 > --- a/drivers/tty/serial/qcom_geni_serial.c > +++ b/drivers/tty/serial/qcom_geni_serial.c > @@ -1107,7 +1107,7 @@ static int qcom_geni_console_setup(struct console *co, char *options) > { > struct uart_port *uport; > struct qcom_geni_serial_port *port; > - int baud = 9600; > + int baud = 115200; > int bits = 8; > int parity = 'n'; > int flow = 'n'; > -- > 2.28.0.618.gf4bc123cb7-goog >