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=-0.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 2AD90C3F68F for ; Fri, 13 Dec 2019 21:16:52 +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 41184206C3 for ; Fri, 13 Dec 2019 21:16:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="c2p3gR7T" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 41184206C3 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 CAA601793; Fri, 13 Dec 2019 14:42:27 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz CAA601793 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1576244597; bh=URl3QpN7+KcP3qD1rO5x0oitl522FjtI1WGDuhj8Suc=; h=Date:From:To:In-Reply-To:References:Cc:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=c2p3gR7TSo4bOJ592w9nS8m3/xCHegx2Ub8gaLcSIt9gsb3NBZ9RXQQ5JBeNbSoEA qen1RNZ6R/+MT+VaA8A7+rC7O6pplGbunvM6i+4KD0kVf7z8zCIi2dA6IPVK56ZniT s8vG5s719qC6NzFOiZl7aVGHaDlBxNAeBwkJpRZE= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 55770F8019B; Fri, 13 Dec 2019 14:42:27 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id E6954F801F4; Fri, 13 Dec 2019 14:42:25 +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 803E2F80139 for ; Fri, 13 Dec 2019 14:42:23 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 803E2F80139 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 919A5AE5E; Fri, 13 Dec 2019 13:42:22 +0000 (UTC) Date: Fri, 13 Dec 2019 14:42:22 +0100 Message-ID: From: Takashi Iwai To: Kai Vehmanen In-Reply-To: References: <20191210145727.22054-1-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") Cc: alsa-devel@alsa-project.org Subject: Re: [alsa-devel] [PATCH] ALSA: hda: Use standard waitqueue for RIRB wakeup 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 Fri, 13 Dec 2019 14:34:13 +0100, Takashi Iwai wrote: > > On Fri, 13 Dec 2019 14:05:31 +0100, > Kai Vehmanen wrote: > > > > Hey, > > > > On Tue, 10 Dec 2019, Takashi Iwai wrote: > > > > > This patch attempts to improve the situation by introducing the > > > standard waitqueue in the RIRB waiter side instead of polling. The > > > > this patch was part of the testing as well, so looks good. One minor > > nit only: > > > > > @@ -216,6 +216,9 @@ void snd_hdac_bus_update_rirb(struct hdac_bus *bus) > > > else if (bus->rirb.cmds[addr]) { > > > bus->rirb.res[addr] = res; > > > bus->rirb.cmds[addr]--; > > > + if (!bus->rirb.cmds[addr] && > > > + waitqueue_active(&bus->rirb_wq)) > > > + wake_up(&bus->rirb_wq); > > > > Checkpath would like to have a comment here: > > > > WARNING: waitqueue_active without comment > > #77: FILE: sound/hda/hdac_controller.c:220: > > + waitqueue_active(&bus->rirb_wq)) > > Yeah, that was known to me, too. Actually it's misleading; what > actually matters is the memory barrier or other synchronization there, > and this should work as is because of the current code path. > (Besides, majority of existing waitqueue_active() have no comments at > all :) > > And, now I found wa_has_sleeper() as a better replacement of > waitqueue_active() that explicitly cares about synchronization. > So I'll change with this in a later patch (after unification to > hda-core). On the second thought, the extra barrier should be utterly superfluous, so I'll go for commenting about the spinlock instead... Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org https://mailman.alsa-project.org/mailman/listinfo/alsa-devel