From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 675E8C43461 for ; Wed, 16 Sep 2020 00:07:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 252F520756 for ; Wed, 16 Sep 2020 00:07:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727248AbgIPAHx (ORCPT ); Tue, 15 Sep 2020 20:07:53 -0400 Received: from relay6-d.mail.gandi.net ([217.70.183.198]:50871 "EHLO relay6-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726863AbgIOO2g (ORCPT ); Tue, 15 Sep 2020 10:28:36 -0400 X-Originating-IP: 90.65.88.165 Received: from localhost (lfbn-lyo-1-1908-165.w90-65.abo.wanadoo.fr [90.65.88.165]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay6-d.mail.gandi.net (Postfix) with ESMTPSA id 86096C001D; Tue, 15 Sep 2020 14:27:43 +0000 (UTC) Date: Tue, 15 Sep 2020 16:27:43 +0200 From: Alexandre Belloni To: Miquel Raynal Cc: Mark Brown , Liam Girdwood , Jaroslav Kysela , Takashi Iwai , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, Thomas Petazzoni Subject: Re: [PATCH 3/3] ASoC: tlv320aic32x4: Enable fast charge Message-ID: <20200915142743.GB9675@piout.net> References: <20200911173140.29984-1-miquel.raynal@bootlin.com> <20200911173140.29984-4-miquel.raynal@bootlin.com> <20200915082602.GH4230@piout.net> <20200915115034.GA5576@sirena.org.uk> <20200915130207.GA9675@piout.net> <20200915141025.GB4913@sirena.org.uk> <20200915161401.54f6d4f3@xps13> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200915161401.54f6d4f3@xps13> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15/09/2020 16:14:01+0200, Miquel Raynal wrote: > Mark Brown wrote on Tue, 15 Sep 2020 15:10:25 > +0100: > > > On Tue, Sep 15, 2020 at 03:02:07PM +0200, Alexandre Belloni wrote: > > > On 15/09/2020 12:50:34+0100, Mark Brown wrote: > > > > On Tue, Sep 15, 2020 at 10:26:02AM +0200, Alexandre Belloni wrote: > > > > > On 11/09/2020 19:31:40+0200, Miquel Raynal wrote: > > > > > > > > + /* > > > > > > + * Enable the fast charging feature and ensure the needed 40ms ellapsed > > > > > > + * before using the analog circuits. > > > > > > + */ > > > > > > + snd_soc_component_write(component, AIC32X4_REFPOWERUP, > > > > > > + AIC32X4_REFPOWERUP_40MS); > > > > > > + msleep(40); > > > > > > + > > > > > > > Maybe the actual REFPOWERUP value could be exposed as a control so > > > > > userspace has a way to set the policy? > > > > > > We very rarely do this, there's not usially anything > > > > > Could you suggest something then? This mainly changes the power > > > codec power consumption. I guess people will want to trade latency > > > for less consumption. > > > > Is it increasing steady state power consumption or is it just drawing > > more power during the ramp (ie, peak current consumption is bigger)? > > Usually this is trading off clean ramps for fast ramps rather than > > affecting steady state. If it's affecting steady state a control seems > > sensible. > > Indeed, it is just affecting the ramp (peak current is bigger). > However, forcing powerup at probe time versus at play time means that you consume power even when not playing audio. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com