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=-3.8 required=3.0 tests=BAYES_00,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 49864C433E0 for ; Fri, 12 Feb 2021 09:25:00 +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 7A61A64D9D for ; Fri, 12 Feb 2021 09:24:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A61A64D9D 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 9733916EB; Fri, 12 Feb 2021 10:24:05 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 9733916EB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1613121895; bh=0fpxF5bEQgar/P9usg9ziXfhyWEk3ffkFK4DikfHMNE=; h=Date:From:To:Subject:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=fnVujRCETyePOZSsRBaY3pu73s2lX6vR7cQt6lnL48GtDmvjcp6mPSVKieedU74FH FJGSVL8TLYBduv17QRX+/h0gNVDvw5xu0Zm21RbeaS4w6duLZSXJOquc+W3LRjeA1S 1XoHWpxaEUkH0Pw9gDKLZNdh2pdZMtKghOKLuR80= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 18AFFF8016C; Fri, 12 Feb 2021 10:24:05 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id D02A2F8022B; Fri, 12 Feb 2021 10:24:03 +0100 (CET) Received: from mx2.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 ECAACF8014B for ; Fri, 12 Feb 2021 10:23:57 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz ECAACF8014B X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 980FDB141; Fri, 12 Feb 2021 09:23:52 +0000 (UTC) Date: Fri, 12 Feb 2021 10:23:52 +0100 Message-ID: From: Takashi Iwai To: Jaroslav Kysela Subject: Re: [PATCH 0/5] ALSA: control - add generic LED trigger code In-Reply-To: <3c84c275-0c62-d2f4-38ad-be6accb3b159@perex.cz> References: <20210211111400.1131020-1-perex@perex.cz> <3c84c275-0c62-d2f4-38ad-be6accb3b159@perex.cz> 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: Hans de Goede , ALSA development , Perry Yuan 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 Thu, 11 Feb 2021 18:53:20 +0100, Jaroslav Kysela wrote: > > Dne 11. 02. 21 v 18:15 Takashi Iwai napsal(a): > > >> Jaroslav Kysela (5): > >> ALSA: control - introduce snd_ctl_notify_one() helper > >> ALSA: control - add layer registration routines > >> ALSA: control - add generic LED trigger module as the new control > >> layer > >> ALSA: HDA - remove the custom implementation for the audio LED trigger > >> ALSA: control - add sysfs support to the LED trigger module > > > One thing I still miss from the picture is how to deal with the case > > like AMD ACP. It has no mixer control to bundle with the LED trigger. > > Your idea is to make a (dummy) user element and tie the LED trigger > > with it? > > Yes, the user-space code which guarantee the silence stream should create an > user space control with the appropriate LED group access bits. The alsa-lib's > softvol PCM plugin can do this silencing for example. What control would it create? In the case of softvol, it's a volume control that really changes the volume. For the mute LED, it's a control turn on/off the mute? If so, I wonder what makes better than creating it from the kernel driver. (Of course, we can list up like "flexibility", etc, but it has a flip side of "complexity" and "fragility"...) > > Another slight concern is the possible regression: by moving the > > mute-LED mode enum stuff into the sysfs, user will get > > incompatibilities after the kernel update. And it's not that trivial > > to change the sysfs entry as default for each user. > > It needs some detailed documentation or some temporary workaround > > (e.g. keep providing the controls for now but warns if the value is > > changed from the default value via the controls). > > I don't think that we have a user space application which is using those > controls (Pulseaudio or so..) in an abstract way. I think that it's really > minor issue. We should probably concentrate for the main designed purpose > (notify about the mute / silent state) and handle those add-on features as an > experimental stuff. I'm sure that there are users of the reverse mic-mute LED ("follow capture" mode); the feature was added because of the explicit request from my colleague, and this mode works no matter whether ALSA native or PA is used. Not sure about "on" and "off" mode; maybe there can be some users who want to disable the LED. But, yes, this is a minor issue and should be in a lower priority. It's just as a reminder. thanks, Takashi