From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932860Ab3GOPWn (ORCPT ); Mon, 15 Jul 2013 11:22:43 -0400 Received: from cassiel.sirena.org.uk ([80.68.93.111]:52410 "EHLO cassiel.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757831Ab3GOPWl (ORCPT ); Mon, 15 Jul 2013 11:22:41 -0400 Date: Mon, 15 Jul 2013 16:22:28 +0100 From: Mark Brown To: Richard Genoud Cc: Nicolas Ferre , Liam Girdwood , Bo Shen , Lars-Peter Clausen , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org, devicetree-discuss@lists.ozlabs.org Message-ID: <20130715152228.GJ11538@sirena.org.uk> References: <1373559359-31607-1-git-send-email-richard.genoud@gmail.com> <1373559359-31607-2-git-send-email-richard.genoud@gmail.com> <20130712114551.GD24508@sirena.org.uk> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="SBT+cnFS/G3NVgv4" Content-Disposition: inline In-Reply-To: X-Cookie: Advancement in position. User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: 94.175.92.69 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [PATCH v5 1/7] sound: codec: wm8731: add rates constraints X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:57:07 +0000) X-SA-Exim-Scanned: Yes (on cassiel.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --SBT+cnFS/G3NVgv4 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Jul 15, 2013 at 04:53:46PM +0200, Richard Genoud wrote: > 2013/7/12 Mark Brown : > > This isn't going to work with systems which have a variable clock as the > > input to the CODEC. If it's imposing constraints the driver needs to > > allow setting the clock to zero as a way of removing constraints (and > > any existing drivers should be updated to do this if needed). > Maybe I'm wrong, but I didn't find any system using variable clock > with this codec. The driver should be written with that possibility in mind even if there were no users; it only takes a couple of lines of code. > The sam9g20ek (soc/atmel/sam9g20_wm8731.c) is not using a crystal, but > it's using a fixed clock anyway. > But there's soc/pxa/corgi.c and soc/pxa/poodle.c that puzzle me. > They seems to use a crystal, but they are setting a different sysclk > depending on the rate. > That seems wrong, but as I'm a newbie in ASoC... Note that the CPU is clock master for those - it's going to be outputting a clock based on the sample rate selected automatically. These boards would be broken by your change as it stands. --SBT+cnFS/G3NVgv4 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.20 (GNU/Linux) iQIcBAEBAgAGBQJR5BOxAAoJELSic+t+oim9mKYP/3FqVkMHE7LlCZvs78y1TbuF yFKdyZvXODyi/OI6I3Znyb8oNk+zwuaf+GI0dq4L2ON+Zl+Z9xRknjRLocP0nR/D QMQjowH6Dt903ENbmYnRTJLyMow3AHp25s2HtM4rTesJPY+Xq8XU9JPU0eL5UVfd zQ4VL3ctfJZk3b24NP96i+euTWvZdZ970J+8tNaqFi0+z9aAGN2lkRr/OI0sXtoT 356PZsfcrxKOmF5KQqB73Zrt7U03JoiZicc8SfOv1RuZAUmr5fpCei6OH7Rxo9+B IovW/Vmu9dDV7cfgaGauFIEwcSgjyxA+bXM1WxiEVUfLirCxGyaMYh/c7QHG0c1D fi65o+y5uH/OUiWDciFqnCfea2uQDq3imnplMM8nF0DDyeLiz44NCNG8PPl0Dhl4 VcTwRE0Tdel0XY+Fv1nBtcT8+NviQuizS7n1MfepWjpql9L8JBAoCF9zyzjS/7BN ErIqW+HT0mqPEBgq7Arvsdd1n94w3BYpps7g8aV6EJMnN24MYibaZIcrC4MZMB/o N6WKIYv5C7Bi00+gedZ4SCkLIesJL9L09oVM8kJFz1LFYHzLpMQoHqpdGvD703TV wHCKcDFukTBnyC/wz67qkqgQzy8RcY56sLuTpj44j2kA+LFVRUdaJChZ7OHzoun2 5dvRqIzZg/hCXtUo8W9G =L2ww -----END PGP SIGNATURE----- --SBT+cnFS/G3NVgv4--