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=-9.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 E507AC43461 for ; Mon, 14 Sep 2020 15:42:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D6FD20E65 for ; Mon, 14 Sep 2020 15:42:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="YttL+ZE8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726454AbgINPmU (ORCPT ); Mon, 14 Sep 2020 11:42:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726044AbgINPjm (ORCPT ); Mon, 14 Sep 2020 11:39:42 -0400 Received: from mail-ot1-x344.google.com (mail-ot1-x344.google.com [IPv6:2607:f8b0:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F899C06178A for ; Mon, 14 Sep 2020 08:39:42 -0700 (PDT) Received: by mail-ot1-x344.google.com with SMTP id g10so304490otq.9 for ; Mon, 14 Sep 2020 08:39:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=jsQOlgmuW5ym+Pa5nus1EZIi7cRnYavzMa7ZkQUAfNI=; b=YttL+ZE88/4HT9qZqo1xUe6VqOTiG71d0Tx4vGcGQt3PL/lm3ZAs44vcRi8s3O5HGE mONQlRVEt/F5F5/NjGOq/B6xCx1Mfgyla/woq377uFZ+dT8/jmHOG2Yu1sMkh8Kh/QB+ rmzs19u13bk5U+ZuAouLcjMjEWt4NQTVcW5l7b9bXLr10PaR2t2TBu+uEmcAoFqPuQFO CAjq4Ry7zFByt8zbyYN1fXeyu5clD5S4mVg+zVPQPgL1z/bonQSUA2SAkvJVQYcqLZ/v KDnmAYzO0H7nbfhIQbJ4sDhMpI0+GASjBRrbpU1ocPeddm2SVAvCbL2BdoaR4/MsB6hy KIGg== 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=jsQOlgmuW5ym+Pa5nus1EZIi7cRnYavzMa7ZkQUAfNI=; b=cqOZvW9OJbv3tFeaU1iiH90PJcbPH4Ry1to3fxv9m209OPKg/I9++BwO9AZGivccvR WI1G62yGihgiBfOWUmXz52fMUfWZX+nzf30lzU7Q3B6jIl3f04RU2Tea3RiTP/iveC8Q om/0dxBZkWyYn0tsOnv14+gSOL1xd7SxqQqolZCNDhmApkRDTYhmd/9c5cwDxPSAxnrk W5f/myOtM0898Xys188XxolcM8iiezqOD8Zlk9BT9B0lkCcgnMUuT0QRQImCA67ZxMV9 U9fhm0MoRxEdns0iDTXYiMDqnZyur7GW16lTcYW4zU2evk8Ylnuko72IMmFvzwyGnUNw 0yvA== X-Gm-Message-State: AOAM5334MuqId+6U9ei0ONUftg/5V3esLLjLgJ4ZCbLSI0X1wDzEyWDV CHBI1xxiFJwDaEpLYUO7IHbcFA== X-Google-Smtp-Source: ABdhPJwFozRzSBv0WDdnzEu0BO/2gv8NycQjAuQPx4hBn62VsNQEpKguodTtgFEZ1OwjBvCY+XU/dg== X-Received: by 2002:a9d:7841:: with SMTP id c1mr10013216otm.318.1600097981295; Mon, 14 Sep 2020 08:39:41 -0700 (PDT) Received: from yoga ([2605:6000:e5cb:c100:8898:14ff:fe6d:34e]) by smtp.gmail.com with ESMTPSA id e30sm3496013otf.49.2020.09.14.08.39.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Sep 2020 08:39:40 -0700 (PDT) Date: Mon, 14 Sep 2020 10:39:35 -0500 From: Bjorn Andersson To: Douglas Anderson Cc: Greg Kroah-Hartman , Nick Desaulniers , robdclark@chromium.org, Akash Asthana , Nathan Chancellor , jwerner@chromium.org, Andy Gross , 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: <20200914153935.GB3715@yoga> 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 11 Sep 10:00 CDT 2020, 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: Bjorn Andersson > Signed-off-by: Douglas Anderson > --- > > 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 >