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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 8C0BFC77B73 for ; Thu, 20 Apr 2023 16:20:19 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 9E101EC2; Thu, 20 Apr 2023 18:19:26 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 9E101EC2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1682007616; bh=+33sxRNf4J0WLdUfWsmmlczxxHuJRrgz+9n9g71/Kew=; h=Date:From:To:Subject:References:In-Reply-To:CC:List-Id: List-Archive:List-Help:List-Owner:List-Post:List-Subscribe: List-Unsubscribe:From; b=dQKNxY9ntiUltbXsxoO7nS07G/gMzajnQZ1MteTqdmCWyXKg5hxK13vUPtXm41gFH QXQfe0haQTKxAtXfZztQcSJHq1qWSj/k9Megwy5itSVGFr5dCukBt9Px1wDnVEzHsG MtvzneuxDsZXtaWvl1iUz7Zt7JfUq2+YKv4shf0Q= Received: from mailman-core.alsa-project.org (mailman-core.alsa-project.org [10.254.200.10]) by alsa1.perex.cz (Postfix) with ESMTP id 0E72BF80149; Thu, 20 Apr 2023 18:19:01 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 4E010F80155; Thu, 20 Apr 2023 18:18:56 +0200 (CEST) Received: from bluemchen.kde.org (bluemchen.kde.org [209.51.188.41]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 9222CF80053 for ; Thu, 20 Apr 2023 18:18:49 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 9222CF80053 Received: from ugly.fritz.box (localhost [127.0.0.1]) by bluemchen.kde.org (Postfix) with ESMTP id 329DF24116; Thu, 20 Apr 2023 12:18:47 -0400 (EDT) Received: by ugly.fritz.box (masqmail 0.3.4, from userid 1000) id 1ppWze-lZD-00; Thu, 20 Apr 2023 18:18:46 +0200 Date: Thu, 20 Apr 2023 18:18:46 +0200 From: Oswald Buddenhagen To: Takashi Iwai Subject: Re: [RFC PATCH] docs: sound: kernel-api: writing-an-alsa-driver.rst: add FIXMEs Message-ID: Mail-Followup-To: Takashi Iwai , alsa-devel@alsa-project.org, Jaroslav Kysela References: <20230405201220.2197878-1-oswald.buddenhagen@gmx.de> <87sfddv7e4.wl-tiwai@suse.de> <87wn26u32c.wl-tiwai@suse.de> <87leimtyqw.wl-tiwai@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <87leimtyqw.wl-tiwai@suse.de> Message-ID-Hash: CM37W324SBKOW3FUAR264UXEED5HO6GZ X-Message-ID-Hash: CM37W324SBKOW3FUAR264UXEED5HO6GZ X-MailFrom: ossi@kde.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-alsa-devel.alsa-project.org-0; header-match-alsa-devel.alsa-project.org-1; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: alsa-devel@alsa-project.org X-Mailman-Version: 3.3.8 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Thu, Apr 20, 2023 at 04:27:35PM +0200, Takashi Iwai wrote: >But why this has to be buried in the middle of a patch containing lots >of other changes...? Better to split out and start a new thread. > this "patch" doesn't contain any changes, only a bunch of questions. given the expected audience, i don't think that "burying" it was detrimental. >IIRC, this was a result after struggles with the structured control >implementations. It became too complex, and the plain array with >string representation can cover all complexity, while it still allows >the grouping in user-space side. > i can see how a keyword based interface description is appealing - it keeps the kernel interface slim and flexible. but of course that comes at a steep cost in user space - i for one got completely lost and was unable to debug the bug described in the OP. maybe a middle way would have been the best option? >Again, the choice was done in a quarter century ago, and if you change >it, you'll certainly break the whole things badly. We must keep the >compatibility. > i don't intend to actually change it. but suppose we did. i suppose we'd have to add SNDRV_CTL_ELEM_ACCESS_{PLAYBACK,CAPTURE}. both could be set for unspecific and actually bidirectional controls. if neither is set, user space would fall back to the keyword based rules (and exceptions ...) - that would be backwards compatible and would enable a gradual migration. regards