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 4404AC433EF for ; Tue, 19 Apr 2022 08:43:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350093AbiDSIqF (ORCPT ); Tue, 19 Apr 2022 04:46:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344219AbiDSIp7 (ORCPT ); Tue, 19 Apr 2022 04:45:59 -0400 Received: from mail-sh.amlogic.com (mail-sh.amlogic.com [58.32.228.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DEB3DB0; Tue, 19 Apr 2022 01:43:16 -0700 (PDT) Received: from [10.18.29.47] (10.18.29.47) by mail-sh.amlogic.com (10.18.11.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.14; Tue, 19 Apr 2022 16:43:13 +0800 Message-ID: <654f9cb8-5a88-3b96-8a2a-80ef7bb5eef9@amlogic.com> Date: Tue, 19 Apr 2022 16:43:13 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH V2 1/2] tty: serial: meson: Add a 12MHz internal clock rate to calculate baud rate in order to meet the baud rate requirements of special BT modules Content-Language: en-US To: Jiri Slaby , Andy Shevchenko CC: "open list:SERIAL DRIVERS" , linux-arm Mailing List , linux-amlogic , Linux Kernel Mailing List , Greg Kroah-Hartman , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl References: <20220418053202.24528-1-yu.tu@amlogic.com> <20220418053202.24528-2-yu.tu@amlogic.com> <9af92c78-73a7-d524-182c-3ebffa69b08a@kernel.org> From: Yu Tu In-Reply-To: <9af92c78-73a7-d524-182c-3ebffa69b08a@kernel.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.18.29.47] X-ClientProxiedBy: mail-sh.amlogic.com (10.18.11.5) To mail-sh.amlogic.com (10.18.11.5) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jiri, Thanks for the tip. On 2022/4/19 15:38, Jiri Slaby wrote: > [ EXTERNAL EMAIL ] > > Hi, > > On 19. 04. 22, 9:29, Yu Tu wrote: >> Hi Andy, >>      Thank you for your advice. >> >> On 2022/4/18 20:09, Andy Shevchenko wrote: >>> [ EXTERNAL EMAIL ] >>> >>> On Mon, Apr 18, 2022 at 8:50 AM Yu Tu wrote: >>>> >>>> A /2 divider over XTAL was introduced since G12A, and is preferred >>>> to be used over the still present /3 divider since it provides much >>>> closer frequencies vs the request baudrate.Especially the BT module >>> >>> 'e. E' (mind the space) >> My statement is a whole. There should be no spaces. > > Period should be followed by a space, of course. I got it .This will be corrected in the next version. > >>>> uses 3Mhz baud rate. 8Mhz calculations can lead to baud rate bias, >>>> causing some problems. >>> >>> ... >>> >>>> +struct meson_uart_data { >>>> +       bool has_xtal_div2; >>> >>> I would prefer to see this as an unsigned int and with a less >>> particular name, e.g. xtal_div would suffice. >> I don't have a problem with your suggestion.Let's see What Neil has to >> say. > > Actually why uint provided it's a boolean value? Or do you mean to store > the divisor directly in this member, Andy? > > thanks,