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 158D4FC6195 for ; Wed, 6 Nov 2019 23:37:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9AD7207FA for ; Wed, 6 Nov 2019 23:37:55 +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 S1728412AbfKFXhy (ORCPT ); Wed, 6 Nov 2019 18:37:54 -0500 Received: from mail-pf1-f196.google.com ([209.85.210.196]:35752 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727029AbfKFXhy (ORCPT ); Wed, 6 Nov 2019 18:37:54 -0500 Received: by mail-pf1-f196.google.com with SMTP id d13so472494pfq.2 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=KINCv3Yl7XZrLya6WbUih2b9ak/pzAbGzzDCpkgWvhtnZkCraIjKm3G3MQRraG0ci7 Yam/GAGwl+nWJIC3lntyVpae7+AaqwZPFRX3QOI3Fw5HZgMKY2opW3MP+conWKj3pS5i 3CbbPvG5Q4ftgke/5Zgz4JR9RdmS/IX49JoZN4LbqGtEhLFVa3CHZg5Q9SCWEn5DcscG i85hKobKwNwTABlnFcL0trR1HVBBXucC4dp5efL5sMb1lWusUPxJ1hTGcPFky9t9M+Rl cZfqmSx9u3L8NFjvpKBDr2t1MHysPHJahFSnQ4qsLpvjDWneT0n7acPPNGuCNOSIEiSw QEvQ== X-Gm-Message-State: APjAAAXhMOIgNXU3UoKZ8xAVj+ytzxk5b4TVAhb1TDDdW8mL3sOanfcQ J7ii4ITb9NJXyVJuiWo1m7KrxQ== 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-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@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.