Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755086AbaBJU1u (ORCPT ); Mon, 10 Feb 2014 15:27:50 -0500 Received: from seldrel01.sonyericsson.com ([212.209.106.2]:16695 "EHLO seldrel01.sonyericsson.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754053AbaBJU1n (ORCPT ); Mon, 10 Feb 2014 15:27:43 -0500 Date: Mon, 10 Feb 2014 12:29:26 -0800 From: Courtney Cavin To: "Ivan T. Ivanov" CC: Andy Gross , Mark Brown , Grant Likely , Rob Herring , "linux-spi@vger.kernel.org" , "linux-arm-msm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , Alok Chauhan , Gilad Avidov , Kiran Gunda , Sagar Dharia Subject: Re: [PATCH 2/2] spi: Add Qualcomm QUP SPI controller support Message-ID: <20140210202926.GV1706@sonymobile.com> References: <1391705868-20091-1-git-send-email-iivanov@mm-sol.com> <1391705868-20091-3-git-send-email-iivanov@mm-sol.com> <20140207073952.GA2610@qualcomm.com> <1391766753.27491.60.camel@iivanov-dev> <20140207173207.GA19974@qualcomm.com> <1392051302.2853.56.camel@iivanov-dev> <20140210174738.GA31596@qualcomm.com> <1392061304.24621.17.camel@violet> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1392061304.24621.17.camel@violet> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 10, 2014 at 08:41:44PM +0100, Ivan T. Ivanov wrote: > > Hi, > > On Mon, 2014-02-10 at 11:47 -0600, Andy Gross wrote: > > On Mon, Feb 10, 2014 at 06:55:02PM +0200, Ivan T. Ivanov wrote: > > > > [....] > > > > > > > > Bail here? > > > > > > > > > > I don't know. What will be the consequences if controller continue to > > > > > operate on its default rate? > > > > > > > > > > > > > It is unclear. But if you can't set the rate that is configured or if there is > > > > a misconfiguration, it's probably better to exit the probe and catch it here. > > > > > > > > > My preference is to delay clock speed change till first > > > SPI transfer. And use wherever transfer itself mandate. > > > > > > > That works. My only concern is that it might be nice to catch a configuration > > problem early rather than wait for the SPI transfer to fail continuously. > > If developer is skilled enough to know which version controller is, > (s)he will be able to put the right frequency constrain here :-) A developer doesn't have to have much skill at all to copy-paste DT configurations around and muck with numbers.... I agree with Andy here, early validation is a good idea here, at the very least, some sanity checks. -Courtney -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/