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=-2.3 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, USER_AGENT_SANE_1 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 D02E5C0650F for ; Tue, 30 Jul 2019 07:59:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F3B220882 for ; Tue, 30 Jul 2019 07:59:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="iQH8RxmO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730708AbfG3H7p (ORCPT ); Tue, 30 Jul 2019 03:59:45 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:34505 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726432AbfG3H7p (ORCPT ); Tue, 30 Jul 2019 03:59:45 -0400 Received: by mail-pg1-f196.google.com with SMTP id n9so23407871pgc.1; Tue, 30 Jul 2019 00:59:44 -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:user-agent; bh=uFAlrmOoAl8QPQdLLMxuBk418ZCFdTVKi3BcwvDs0DE=; b=iQH8RxmOMF5875eeVO3Da2rdPhB9lA11lpzfN+ZfJVN6bm6r3rR50pnI5vhkCm7k+g SUMsV8rxeWoqmqKfla+d0wSLqBH9tkHZw8vYjdrAlyn92qrZDyQS0SMIymzafGxM+aJY P/NqNF9VN0J2K5ZXFK9p3H7ihv69ui83yfoKZmK2tvmkyDVcZzCTXGvmHYjBZDwDhv+B pspDjFP0Wcqd+CTawX04gl/d4KuzyPfRUZoOsvFWOF5/chtuOm/0ngK0rJrd7bSwrxJO jyiETiHeMJA+L81L9x6Qx272zjSzcoU2tjxj8SZfGBBVk78EjwO3ldCfct6uJJ38Sb5P 9tZQ== 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:user-agent; bh=uFAlrmOoAl8QPQdLLMxuBk418ZCFdTVKi3BcwvDs0DE=; b=EB6FDH3NNKzpITmfSsZ1elLJQSmHw5Zw5PT0yn+w5H1zwpE9GAV5KvM15F0Jc290hL X9jLwY+4cQpDniSbdbe5s3GgtRG4glkLCEjYwX3ruFEzzI8WIghkHr9qmT8JRCV64Mwx tVhzn9r8U/mTV2fRDRYZE3j+RYT5XCiHLR1WE5u1HcsqvYZi3Qr1E47RTw8/VB8pqgvr sMkpwAjX8PuclpFYKd6H4RB/PHykWtjHL6A5f08FWXU8uqK//6ZSVaVGhhR+nJLWUF7W TIT1XqN6RdxGZUQ51olr4+yXxY7DpQ56nyIHI7vGNS6g0fjAgOepinYO81GRWpOuG6YB HwSw== X-Gm-Message-State: APjAAAWkqWzSOvNk5/nlctcCiMT9u/A5g0V5JvoEOr5p8URWUJXmkwZp s6Smagf5gQzvv0v5ZYrWRrc= X-Google-Smtp-Source: APXvYqwzj4cH6/cG01FQ79ISBwq4FGUEBV1C6SsIzTEU3Ib99EXqnyks6RgcY8HCH6FCulwOfpSo5A== X-Received: by 2002:a63:e213:: with SMTP id q19mr106419831pgh.180.1564473584219; Tue, 30 Jul 2019 00:59:44 -0700 (PDT) Received: from Asurada (c-98-248-47-108.hsd1.ca.comcast.net. [98.248.47.108]) by smtp.gmail.com with ESMTPSA id 33sm74160050pgy.22.2019.07.30.00.59.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 30 Jul 2019 00:59:43 -0700 (PDT) Date: Tue, 30 Jul 2019 00:59:35 -0700 From: Nicolin Chen To: Mark Brown Cc: Daniel Baluta , Daniel Baluta , Devicetree List , Linux-ALSA , Pengutronix Kernel Team , Timur Tabi , Rob Herring , "S.j. Wang" , "Angus Ainslie (Purism)" , Takashi Iwai , Linux Kernel Mailing List , dl-linux-imx , Viorel Suman , Fabio Estevam , Mihai Serban , Lucas Stach Subject: Re: [alsa-devel] [PATCH v2 1/7] ASoC: fsl_sai: Add registers definition for multiple datalines Message-ID: <20190730075934.GA5892@Asurada> References: <20190728192429.1514-1-daniel.baluta@nxp.com> <20190728192429.1514-2-daniel.baluta@nxp.com> <20190729194214.GA20594@Asurada-Nvidia.nvidia.com> <20190729202001.GC4787@sirena.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190729202001.GC4787@sirena.org.uk> User-Agent: Mutt/1.5.22 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 29, 2019 at 09:20:01PM +0100, Mark Brown wrote: > On Mon, Jul 29, 2019 at 10:57:43PM +0300, Daniel Baluta wrote: > > On Mon, Jul 29, 2019 at 10:42 PM Nicolin Chen wrote: > > > On Sun, Jul 28, 2019 at 10:24:23PM +0300, Daniel Baluta wrote: > > > > > @@ -704,7 +711,14 @@ static bool fsl_sai_readable_reg(struct device *dev, unsigned int reg) > > > > case FSL_SAI_TCR3: > > > > case FSL_SAI_TCR4: > > > > case FSL_SAI_TCR5: > > > > - case FSL_SAI_TFR: > > > > + case FSL_SAI_TFR0: > > > > A tricky thing here is that those SAI instances on older SoC don't > > > support multi data lines physically, while seemly having registers > > > pre-defined. So your change doesn't sound doing anything wrong to > > > them at all, I am still wondering if it is necessary to apply them > > > to newer compatible only though, as for older compatibles of SAI, > > > these registers would be useless and confusing if being exposed. > > > > What do you think? > > > Yes, I thought about this too. But, I tried to keep the code as short > > as possible and technically it is not wrong. When 1 data line is supported > > for example application will only care about TDR0, TFR0, etc. > > So long as it's safe to read the registers (you don't get a bus error or > anything) I'd say it's more trouble than it's worth to have separate > regmap configuations just for this. The main reasons for restricting > readability are where there's physical problems with doing the reads or > to keep the size of the debugfs files under control for usability and > performance reasons. Thanks for the input, Mark. Daniel, did you get a chance to test it on older SoCs? At least nothing breaks like bus errors?