linux-kernel - Re: [PATCH 3/3] ASoC: tlv320aic32x4: Enable fast charge

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Date:   Tue, 15 Sep 2020 15:10:25 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Alexandre Belloni <alexandre.belloni@...tlin.com>
Cc:     Miquel Raynal <miquel.raynal@...tlin.com>,
        Liam Girdwood <lgirdwood@...il.com>,
        Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>, alsa-devel@...a-project.org,
        linux-kernel@...r.kernel.org,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>
Subject: Re: [PATCH 3/3] ASoC: tlv320aic32x4: Enable fast charge

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.

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