From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755457AbbLDQhT (ORCPT ); Fri, 4 Dec 2015 11:37:19 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:58394 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754087AbbLDQhQ (ORCPT ); Fri, 4 Dec 2015 11:37:16 -0500 Date: Fri, 4 Dec 2015 17:37:09 +0100 From: Pavel Machek To: Mark Brown Cc: Anatol Pomozov , LKML Subject: Re: [PATCH] regmap: Add a config option for making regmap debugfs writable Message-ID: <20151204163709.GA822@amd> References: <1444758415-5190-1-git-send-email-anatol.pomozov@gmail.com> <20151013175519.GL14956@sirena.org.uk> <20151013200700.GM14956@sirena.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151013200700.GM14956@sirena.org.uk> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 2015-10-13 21:07:00, Mark Brown wrote: > On Tue, Oct 13, 2015 at 11:33:13AM -0700, Anatol Pomozov wrote: > > On Tue, Oct 13, 2015 at 10:55 AM, Mark Brown wrote: > > > > This is deliberately not a Kconfig option because it is a terrible idea > > > to do this in production and making it either selectable or the default > > > is an invitation to abuse. > > > What kind of abuse are you talking about? > > Using it as a standard interface to control systems in production rather > than having appropriate support in the relevant driver. > > > Having an easy way of modifying chip registers is extremely useful > > during bringup / driver development. And during device development > > phase I regularly have situations when I need to change a register to > > see if it fixes an issue. Sometimes I need to test it remotely when > > users located at another end of the Earth. > > This is exactly the sort of use case this feature is intended for, and > is the sort of situation where a custom kernel is not going to be any > kind of practical problem. Well.. we support iopl(0) and we have /dev/mem. I don't see how this is different. And yes, CONFIG_ option would be nice, so that this gets compile test coverage.... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html