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=-2.4 required=3.0 tests=DKIM_SIGNED, MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID,USER_AGENT_MUTT 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 60CD7C476E5 for ; Thu, 12 Jul 2018 15:58:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0D3F221471 for ; Thu, 12 Jul 2018 15:58:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sirena.org.uk header.i=@sirena.org.uk header.b="ZR78c0eU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0D3F221471 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732284AbeGLQIf (ORCPT ); Thu, 12 Jul 2018 12:08:35 -0400 Received: from heliosphere.sirena.org.uk ([172.104.155.198]:50984 "EHLO heliosphere.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726725AbeGLQIf (ORCPT ); Thu, 12 Jul 2018 12:08:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sirena.org.uk; s=20170815-heliosphere; h=In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=rxWNbK8Y0p66Z9w0AVbWsVr4o2fqRHBIIdsEUhakLWY=; b=ZR78c0eUYVOoyrArBu5iKKCq9 PGrRSuu4yy0EU3TWeDp4BW20AUhZDOdPKpfqWJOWrZSJGqApzMxw+j0BUOCLaaspQ0FWafmAHjTpG ianeKm1lBEvhUkyhL1sdiXSZ9GNzrgfdbpKkZ0HDCiQZ97E9cILbzf2Sn9xEbcKXdagJU=; Received: from debutante.sirena.org.uk ([2001:470:1f1d:6b5::3] helo=debutante) by heliosphere.sirena.org.uk with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1fddz0-0003ny-Lb; Thu, 12 Jul 2018 15:58:18 +0000 Received: from broonie by debutante with local (Exim 4.91) (envelope-from ) id 1fddyz-0006vj-W9; Thu, 12 Jul 2018 16:58:18 +0100 Date: Thu, 12 Jul 2018 16:58:17 +0100 From: Mark Brown To: Takashi Iwai Cc: Pierre-Louis Bossart , alsa-devel@alsa-project.org, lgirdwood@gmail.com, Srinivas Kandagatla , bgoswami@codeaurora.org, rohitkr@codeaurora.org, vkoul@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [alsa-devel] [PATCH] ASoC: core: add support to card re-bind/unbind using component framework Message-ID: <20180712155817.GG10369@sirena.org.uk> References: <20180711084318.11786-1-srinivas.kandagatla@linaro.org> <68715fbc-9447-dfaf-3fe5-4200684c2cbc@linux.intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="GdbWtwDHkcXqP16f" Content-Disposition: inline In-Reply-To: X-Cookie: Kleeneness is next to Godelness. User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --GdbWtwDHkcXqP16f Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Jul 12, 2018 at 05:42:30PM +0200, Takashi Iwai wrote: > Pierre-Louis Bossart wrote: > > On 7/11/18 3:43 AM, Srinivas Kandagatla wrote: > > > This patch aims at add achieving dynamic behaviour of audio card when > > > the dependent components disappear and reappear. > > Humm, no real comment on this patch proper but rather on how userspace > > would deal with this dynamic behavior? > > We had similar opens when we worked on the BYT/CHT HDMI stuff and > > ended-up with quite a few issues in userspace (PulseAudio mainly) > > related to dynamic behavior at the kernel level as a result of > > plug/unplug. Also not sure how an Android HAL would deal with a card > > disappearing temporarily if DSP resources become unavailable or > > unresponsive. Any thoughts or guidance you might think of? > Was the card-level register / unregister really problematic with PA? > It's basically similar as the hotplug like USB, so I thought it would > work as is. Yeah, I'd expect normal desktop stuff to be able to cope with this due to physically hotpluggable hardware. The main use case for doing things like this with module unload is in a development context where hopefully people can also arrange to use a userspace that can cope or to do whatever to reset it, any limitations in some userspace shouldn't prevent people from having the facility available. --GdbWtwDHkcXqP16f Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAltHepkACgkQJNaLcl1U h9AMIwf7BhRkGokjgqRqrNGjXZa6Kwykx4hHriSACyNkX7n9KrQJnmZjM7DYZ6sl sNQIJL5AUetE0Swwtk5pQpYsqnBO0/yPSwCDthWu9gzTLC1o95LTVaJb+g5RtrJt i65c6oKpL+UZ0ALa3FvUwSNOvnpQOvIg5X+ATPhXN8MajRFC/SxK456Pi52pR6Eo lJ6TowhzK8lYfft2edbh2Z4XZA3X2YvOEBvgo0VWcd8eWQ6ive9Y2D8BhVoBFaWZ 98DOLCBvNhFmN/1mPSr56nQS/lEgF736wbNzOa2t3/lvLrS5ykkB3XzZv+Y/70o3 /DyeAr2GtVEJp2TLt23wkZgDhe0LFQ== =nrKD -----END PGP SIGNATURE----- --GdbWtwDHkcXqP16f--