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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C4FC4C432C3 for ; Wed, 13 Nov 2019 16:41:48 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9F41E2068E for ; Wed, 13 Nov 2019 16:41:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="SUyi16nh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9F41E2068E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 7A5511612; Wed, 13 Nov 2019 17:40:56 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 7A5511612 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1573663306; bh=X1Ih0FUr4S+Gi2ZjF+zsA0wCxeEWxbO6raq5Lu8wDEY=; h=Date:From:To:In-Reply-To:References:Cc:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=SUyi16nhJLgP14zTAlFVMmA6GupNEDkWSGNnMm945GwTJ5YWaqI4qPR81WEhupnJv PRoDR9CBPblFqRjp2+kJz5y54lSUL44bIi58AnC2XkCIqlhK4CkBdC26qLYejutnOg 7y92QDMRrPA3eglQxmr7DcxMXq6cngleLzwR23AI= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id EEECFF8007E; Wed, 13 Nov 2019 17:40:55 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id AA0A9F80086; Wed, 13 Nov 2019 17:40:53 +0100 (CET) Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 725F8F80084 for ; Wed, 13 Nov 2019 17:40:48 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 725F8F80084 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 5F9A6ACA7; Wed, 13 Nov 2019 16:40:44 +0000 (UTC) Date: Wed, 13 Nov 2019 17:40:43 +0100 Message-ID: From: Takashi Iwai To: Arnd Bergmann In-Reply-To: References: <20191112151642.680072-1-arnd@arndb.de> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Cc: ALSA Development Mailing List , y2038 Mailman List , "linux-kernel@vger.kernel.org" , Takashi Iwai , Mark Brown , Baolin Wang Subject: Re: [alsa-devel] [PATCH v6 0/8] Fix year 2038 issue for sound subsystem X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" On Wed, 13 Nov 2019 15:32:44 +0100, Arnd Bergmann wrote: > > On Tue, Nov 12, 2019 at 9:37 PM Takashi Iwai wrote: > > On Tue, 12 Nov 2019 16:16:34 +0100, Arnd Bergmann wrote: > > > I would like to propose merging this into the alsa tree after > > > the v5.5 merge window for inclusion into v5.6, to allow a good > > > amount of testing, in particular for the header changes that > > > may cause problems for user space applications. > > > > Agreed, it's still no urgent problem. > > I actually do think it's getting urgent, anything that touches > the ABI must be done carefully and not rushed. > > The urgency at the moment is that developers are starting to > deploy systems with 64-bit time_t with musl-libc making this > the default now, and 32-bit risc-v not offering 32-bit time_t at all. > > At the moment, this means that audio support is broken for > them, and that needs to be fixed. > > The other reason why lots of people care about moving all user > space to 64-bit time_t is that 32-bit hardware is slowly starting > to become less common. We know there will still be many > 32-bit ARM systems operational in 2038, but most of them will > be on (then) 10+ year old hardware, running even older software > that already being worked on today. The longer it takes us to > stop using 32-bit time_t in user space, the more systems will > end up having to be thrown away rather than fixed. Don't worry, I planned merging the whole changes for 5.6. > > So now taking a quick look through the series, I find this approach is > > the way to go. Although one might get a bit more optimization after > > squeeze, it's already a good compromise between the readability and > > the efficiency. > > Thanks! > > > A slight uncertain implementation is the timer tread stuff, especially > > the conditional definition of SNDRV_TIMER_IOCTL_TREAD (IIRC, I already > > complained it in the past, too). But I have no other idea as well, so > > unless someone else gives a better option, we can live with that. > > We had discussed alternatives for this one last time, and decided > to go with the solution I posted here. The main alternative would > be to change the 'timespec' in snd_timer_tread to a fixed-length > structure based on two 'long' members. This would avoid the > need to match the command with the time_t type, but the cost would > be requiring CLOCK_MONOTONIC timestamps to avoid the > overflow, and changing all application source code that requires > the type to be compatible with 'timespec'. Fair enough. One thing I forgot to mention: when we add/modify the ioctl or ABI, we need to increment the protocol version, e.g. SNDRV_PCM_VERSION to indicate user-space the supported ABI. Please change these in your next patches, too. thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org https://mailman.alsa-project.org/mailman/listinfo/alsa-devel