From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: question on dapm_reg_event() Date: Wed, 6 Jan 2010 15:59:17 +0000 Message-ID: <20100106155917.GA11245@rakim.wolfsonmicro.main> References: <771cded01001041810n490145ednefccea066eaf271a@mail.gmail.com> <20100106145321.GC5783@sirena.org.uk> <20100106174859.227f1cd8.jhnikula@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from opensource2.wolfsonmicro.com (opensource.wolfsonmicro.com [80.75.67.52]) by alsa0.perex.cz (Postfix) with ESMTP id 50AF02454C for ; Wed, 6 Jan 2010 16:59:19 +0100 (CET) Content-Disposition: inline In-Reply-To: <20100106174859.227f1cd8.jhnikula@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Jarkko Nikula Cc: alsa-devel@alsa-project.org, Haojian Zhuang List-Id: alsa-devel@alsa-project.org On Wed, Jan 06, 2010 at 05:48:59PM +0200, Jarkko Nikula wrote: > Mark Brown wrote: > > Hrm, no, that's not at all clear to me either. CCing Jarkko who > > contributed the register write control originally. > IIRC, there were some reason to avoid register update by the > dapm_update_bits and negative register value was used to prevent it. > Reg+1 makes sure that the value is negative also for register 0. Ah, you're using some of the shared fields that the generic widget handling code then tries to interpret itself. It'd probably be less surprising to special case this widget in the generic code (as we do in a few other cases, like the PGA ramping).