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=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL 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 299E0FC6195 for ; Wed, 6 Nov 2019 23:37:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE18B207FA for ; Wed, 6 Nov 2019 23:37:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Ws7n2u3+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727972AbfKFXhx (ORCPT ); Wed, 6 Nov 2019 18:37:53 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:40427 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727029AbfKFXhw (ORCPT ); Wed, 6 Nov 2019 18:37:52 -0500 Received: by mail-pf1-f195.google.com with SMTP id r4so441719pfl.7 for ; Wed, 06 Nov 2019 15:37:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=I8dPU8PsIcjQN/qde2NZnnh3S5qLVWrToiL1ovmtnNY=; b=Ws7n2u3+b3+8KEXtZJewZYqykECNj6uA47mb/cDxScvuF7J8mD7C4qC58TQwUWfOhT zKiLyWDL8556asRqUA4bS5qUDJ0dNIFZ5veM3tP5KuIsKIMokH1TKDBFqiom+XC8B1n0 T4MJXSSrD/wBLaLOdl4fL46deH893TQucIACAhPYdYId3aUBQigD5B1NgQDTvLr895qH ZUTosV/4fPVHtkzn8PKNYjX0OcXZebWpXVqxVFWTLQxBC6S6dnG7vqt608q65h7A3kJd bzeRGGVDTubEzwqtBiAnP7BRNsQnygMFmWlEtVzOeKChMgHte95VNYuCzUszrzSSQc7Z KhbQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=I8dPU8PsIcjQN/qde2NZnnh3S5qLVWrToiL1ovmtnNY=; b=LAof+GwM76rwO6HaUykMz/0v9YHpJNDhkXHX7KmFfrzFDJPxKS1UQuYb+L8NtUQ9hy SUKVop95sfjo0F+oPcgxnYFCPL1lwSRNGTSRgdF/9h+Tb5lLjZ8Ps9PiuyMn0kae3cr7 TeKD8mueNuNrwKF58BNg9JmFuFZOqpSfpckvYo0NDFqsYkQFlSzBz/5xE1UWclRfbuwx Jjwc8qt4LyDfSCb5NZ3kRZ64u9z3rrTOg7r0RVDFgJJnRcwqUkcWHHQZ1gg1yUoVBg53 YxWLXyIlcg00eFWi7XAI1XFEW0LyRk3KAN+9cRhWlCgjfDXHXXBfQKamVAJdCsEGnMw8 ZBRA== X-Gm-Message-State: APjAAAWxyb1E9LeAJa+SxRuAXYUMNL8qFZesyCIkQAzW3NNLllMvMPsJ wplM8fn/tGRiKvvGD5yuo/UdpQ== X-Google-Smtp-Source: APXvYqw9iZMhdp6QP4E2+vOP8jk/LTcrF0hI26oCv/HF5wbRGuVeoDYZzb1ZlU6yuqTo+vQkhG8n+Q== X-Received: by 2002:a63:181f:: with SMTP id y31mr592777pgl.186.1573083471320; Wed, 06 Nov 2019 15:37:51 -0800 (PST) Received: from smuckle.san.corp.google.com ([2620:15c:2d:3:8fbe:ee3b:c81d:238d]) by smtp.gmail.com with ESMTPSA id i13sm92639pfo.39.2019.11.06.15.37.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 06 Nov 2019 15:37:50 -0800 (PST) Subject: Re: [PATCH] rtc: class: support hctosys from modular RTC drivers To: Alexandre Belloni Cc: Alessandro Zummo , linux-kernel@vger.kernel.org, linux-rtc@vger.kernel.org, kernel-team@android.com References: <20191106194625.116692-1-smuckle@google.com> <20191106231923.GK8309@piout.net> From: Steve Muckle Message-ID: Date: Wed, 6 Nov 2019 15:37:49 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191106231923.GK8309@piout.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/6/19 3:19 PM, Alexandre Belloni wrote: > On 06/11/2019 11:46:25-0800, Steve Muckle wrote: >> Due to distribution constraints it may not be possible to statically >> compile the required RTC driver into the kernel. >> >> Expand RTC_HCTOSYS support to cover all RTC devices (statically compiled >> or not) by checking at the end of RTC device registration whether the >> time should be synced. >> > > This does not really help distributions because most of them will still > have "rtc0" hardcoded and rtc0 is often the rtc that shouldn't be used. Just for my own edification, why is that? Is rtc0 normally useless on PC for some reason? On the platforms I'm working with I believe it can be assured that rtc0 will be the correct rtc. That doesn't help typical distributions though. What about a kernel parameter to optionally override the rtc hctosys device at runtime? > Can't you move away from HCTOSYS and do the correct thing in userspace > instead of the crap hctosys is doing? Yes, I just figured it's a small change, and if hctosys can be made to work might as well use that.