From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754732AbaIQBdH (ORCPT ); Tue, 16 Sep 2014 21:33:07 -0400 Received: from mail-bl2on0140.outbound.protection.outlook.com ([65.55.169.140]:53184 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754618AbaIQBdF (ORCPT ); Tue, 16 Sep 2014 21:33:05 -0400 X-Greylist: delayed 125057 seconds by postgrey-1.27 at vger.kernel.org; Tue, 16 Sep 2014 21:33:05 EDT Date: Wed, 17 Sep 2014 09:32:52 +0800 From: Shawn Guo To: Nicolin Chen CC: Shengjiu Wang , , , , , , , , , Subject: Re: [PATCH] ASoC: fsl_spdif: don't change the root clock rate of spdif in driver Message-ID: <20140917013251.GA4796@dragon> References: <1410867994-32138-1-git-send-email-shengjiu.wang@freescale.com> <20140916180028.GA6784@Asurada> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20140916180028.GA6784@Asurada> User-Agent: Mutt/1.5.21 (2010-09-15) X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:192.88.168.50;CTRY:US;IPV:CAL;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10019020)(6009001)(199003)(24454002)(189002)(51704005)(86362001)(6806004)(21056001)(20776003)(23726002)(85306004)(33656002)(1411001)(92566001)(110136001)(99396002)(4396001)(50986999)(46406003)(105606002)(83072002)(106466001)(76176999)(97756001)(97736003)(107046002)(64706001)(54356999)(83322001)(33716001)(102836001)(31966008)(84676001)(44976005)(95666004)(87936001)(92726001)(26826002)(85852003)(104016003)(68736004)(81342003)(46102003)(77982003)(83506001)(50466002)(47776003)(76482002)(57986006)(81542003)(79102003)(80022003)(74662003)(74502003)(90102001);DIR:OUT;SFP:1102;SCL:1;SRVR:BY2PR0301MB0615;H:tx30smr01.am.freescale.net;FPR:;MLV:ovrnspm;PTR:InfoDomainNonexistent;A:1;MX:1;LANG:en; X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:;UriScan:; X-Forefront-PRVS: 0337AFFE9A Authentication-Results: spf=fail (sender IP is 192.88.168.50) smtp.mailfrom=Shawn.Guo@freescale.com; X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 16, 2014 at 11:19:28AM -0700, Nicolin Chen wrote: > On Tue, Sep 16, 2014 at 07:46:34PM +0800, Shengjiu Wang wrote: > > The spdif root clock may be used by other module or defined with > > CLK_SET_RATE_GATE, so we can't change the clock rate in driver. > > In this patch remove the clk_set_rate and clk_round_rate to protect the > > clock. > > It's a quite convenient and conservative way to remove the clock > dealing code in the driver, however, it may result less flexible > functionalities. > > The reason why I left the clk_set_rate() in the driver is to hope > we may find a better way to tackle those tough situations. For IP > itself, it doesn't matter if the clock the SoC provides to it is > being shared by other modules or not. > > So I think, if it's a shared clock, we should not define it as a > rate-changeable one in the SoC level, as we might still have some > SoCs provide a dedicated clock to S/PDIF so as to get the maximum > range of clock support for users. > > @Shawn > Sorry to involve you in this topic. I'm not so sure if we can do > this in the clock driver so that the clock rate would be fixed > even if the driver is trying to change it. If we can, I think we > may use a better solution here instead. No, we do not have anything like that today. Shawn