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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 ABC28C4338F for ; Sat, 14 Aug 2021 06:43:37 +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 29ABD60EFE for ; Sat, 14 Aug 2021 06:43:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 29ABD60EFE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=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 ADB7417C3; Sat, 14 Aug 2021 08:42:45 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz ADB7417C3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1628923415; bh=096/3vIrkzGJ4P6/BT96g5hdNK5KfNMrpZ+R9llgpaQ=; h=Date:From:To:Subject:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=nqp2fa0m6ddCb3b9C/HWmZ7ga+h4s4IY2wUPxw8DyuWJV5qaruZzFtB7y9bCijUJt usSK7YDz1yeo+X8qzhJO/7JpQsyC+ZAKbghHX9oiw62Vv5UenODzfSH/oJLDa5dDaY 38g/OD7MWJIj68hqkvv7Nwy8r/VM8y1hdqJ+sx8A= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 4692EF802A0; Sat, 14 Aug 2021 08:42:27 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 32E2BF804B1; Sat, 14 Aug 2021 08:42:26 +0200 (CEST) Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id ED96AF8025D for ; Sat, 14 Aug 2021 08:42:19 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz ED96AF8025D Authentication-Results: alsa1.perex.cz; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="XWHifQsX"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="T1P1Usdw" Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id EE35422147; Sat, 14 Aug 2021 06:42:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1628923338; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=VtCftruiwd82OTy1PtvwvobWVRHNnnQK3ux9AXqFyXo=; b=XWHifQsXPE/Av1e/mtxtEJP5Pww3AFiioaOWVzWiPAUlOP+wG1f6FYADGm+ms2DXXzAMA0 H80L4o98kSz3JNwJhFlGFBrSLO8brd859OJIDc/5b83lsVvQQVwmXvzZKJpaAWNuDtgEJo iUKO5l3fZ6Lrs37JoVtg53s7BR4bk74= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1628923338; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=VtCftruiwd82OTy1PtvwvobWVRHNnnQK3ux9AXqFyXo=; b=T1P1UsdwggRcr4ROdsgQYb3Ks026jIxsnpLfg3pkRh7di2Ze9R41veLVPd7W/6Wu0FirFG NPgJ5aLXFv6EcXCg== Received: from alsa1.suse.de (alsa1.suse.de [10.160.4.42]) by relay2.suse.de (Postfix) with ESMTP id D4D21A3B85; Sat, 14 Aug 2021 06:42:18 +0000 (UTC) Date: Sat, 14 Aug 2021 08:42:18 +0200 Message-ID: From: Takashi Iwai To: Takashi Iwai Subject: Re: [PATCH] ALSA: pcm: Add SNDRV_PCM_INFO_EXPLICIT_SYNC flag In-Reply-To: <20210813082142.5375-1-tiwai@suse.de> References: <20210813082142.5375-1-tiwai@suse.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") Content-Type: text/plain; charset=US-ASCII Cc: alsa-devel@alsa-project.org, Pierre-Louis Bossart 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: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" On Fri, 13 Aug 2021 10:21:42 +0200, Takashi Iwai wrote: > > ALSA PCM core has an optimized way to communicate with user-space for > its control and status data via mmap on the supported architectures > like x86. Depending on the situation, however, we'd rather want to > enforce user-space notifying the applptr or hwptr change explicitly > via ioctl. For example, the upcoming non-contig and non-coherent > buffer handling would need an explicit sync, and this needs to catch > the applptr and hwptr changes. Also, ASoC SOF driver will have the > SPIB support that has the similar requirement for the explicit control > of the applptr and hwptr. > > This patch adds the new PCM hardware info flag, > SNDRV_PCM_INFO_EXPLICIT_SYNC. When this flag is set, PCM core > disables both the control and the status mmap, which enforces > user-space to update via SYNC_PTR ioctl. In that way, drivers can > catch the applptr and hwptr update and apply the sync operation if > needed. > > Link: https://lore.kernel.org/r/20210812113818.6479-1-tiwai@suse.de > Link: https://lore.kernel.org/r/20210610205326.1176400-1-pierre-louis.bossart@linux.intel.com > Signed-off-by: Takashi Iwai Now merged to for-next branch. Takashi