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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 D5E8EC2B9F8 for ; Tue, 25 May 2021 09:27:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7EAA61360 for ; Tue, 25 May 2021 09:27:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232475AbhEYJ3K (ORCPT ); Tue, 25 May 2021 05:29:10 -0400 Received: from mx2.suse.de ([195.135.220.15]:54264 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232530AbhEYJ3F (ORCPT ); Tue, 25 May 2021 05:29:05 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1621934855; 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=fQlYaaBAybmBVUAGlRLhcaeBlT3WUi4ttbQdnsQvkkc=; b=Z5IFxkkqBLurgeYrmix32ALtnLT8lESgjZwzcw8pSHjE1t+wVxLtaTAnEY84Yd8srphYjb DXNkN7/1wWh/OZndYtoGp7JzrnNS1qEB+GU+VdSDfY2HXaraGUWGpzKArrrq7N0sgT1kWp smaoRynoJTMxNcR8pCYrm/mLTnIusIg= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1621934855; 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=fQlYaaBAybmBVUAGlRLhcaeBlT3WUi4ttbQdnsQvkkc=; b=w5nx12E3s3jTBrzYYio/pTtjlRrpP2if1P01HcjOBFvnQvkKvT9WoFa60nHBjeZKOVFGfl MfRFxF961C/czXCg== Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id CF558AECB; Tue, 25 May 2021 09:27:34 +0000 (UTC) Date: Tue, 25 May 2021 11:27:34 +0200 Message-ID: From: Takashi Iwai To: Maxime Ripard Cc: Mark Brown , Takashi Iwai , Liam Girdwood , Jaroslav Kysela , dri-devel@lists.freedesktop.org, Daniel Vetter , David Airlie , Maarten Lankhorst , Thomas Zimmermann , devicetree@vger.kernel.org, alsa-devel@alsa-project.org, Dom Cobley , Tim Gover , Dave Stevenson , linux-kernel@vger.kernel.org, Eric Anholt , Rob Herring , bcm-kernel-feedback-list@broadcom.com, Nicolas Saenz Julienne , Daniel Vetter , Phil Elwell , linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org Subject: Re: [PATCH 00/11] drm/vc4: hdmi: Enable Channel Mapping, IEC958, HBR Passthrough using hdmi-codec In-Reply-To: <20210525092353.mvqdv4bi4i4rkqsu@gilmour> References: <20210507140334.204865-1-maxime@cerno.tech> <20210524133904.kgkh6xd3m5c2j3xa@gilmour> <20210525092353.mvqdv4bi4i4rkqsu@gilmour> 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 25 May 2021 11:23:53 +0200, Maxime Ripard wrote: > > Hi Takashi, > > On Tue, May 25, 2021 at 10:35:14AM +0200, Takashi Iwai wrote: > > On Mon, 24 May 2021 15:39:04 +0200, > > Maxime Ripard wrote: > > > > > > Hi, > > > > > > On Fri, May 07, 2021 at 04:03:23PM +0200, Maxime Ripard wrote: > > > > Hi, > > > > > > > > hdmi-codec allows to have a lot of HDMI-audio related infrastructure in place, > > > > it's missing a few controls to be able to provide HBR passthrough. This series > > > > adds more infrastructure for the drivers, and leverages it in the vc4 HDMI > > > > controller driver. > > > > > > > > One thing that felt a bit weird is that even though > > > > https://www.kernel.org/doc/html/latest/sound/kernel-api/writing-an-alsa-driver.html#iec958-s-pdif > > > > mentions that the iec958 mask control should be a mixer control and the > > > > default control should be a PCM one, it feels a bit weird to have two different > > > > control type for two controls so similar, and other drivers are pretty > > > > inconsistent with this. Should we update the documentation? > > > > > > Any comments on this series? > > > > A patch for updating the documentation is welcome. > > Currently, as de facto standard, we allow both MIXER and PCM ifaces > > for all IEC958-related controls, and it's unlikely that we would > > change that in future. > > Ok, I'll write a patch for the documentation make it clearer then :) > > Do we want to make sure that all the iec958 controls are on the same > iface, or is it also left to the driver (or should we just leave the > existing drivers as is but encourage a consistent use in the future)? I'd leave the existing drivers as-is. Changing the iface is basically an incompatible change, and although most of applications and alsa-lib should look at both ifaces, there can be any surprise by that change. thanks, Takashi