linux-kernel - Re: [PATCH v3 2/5] ASoC: codecs: wsa883x: lower default PA gain

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Message-ID: <Zaordb030PebNR8h@hovoldconsulting.com>
Date: Fri, 19 Jan 2024 08:57:41 +0100
From: Johan Hovold <johan@...nel.org>
To: Mark Brown <broonie@...nel.org>
Cc: Johan Hovold <johan+linaro@...nel.org>,
	Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
	Banajit Goswami <bgoswami@...cinc.com>,
	Liam Girdwood <lgirdwood@...il.com>,
	Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.com>,
	alsa-devel@...a-project.org, linux-sound@...r.kernel.org,
	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH v3 2/5] ASoC: codecs: wsa883x: lower default PA gain

On Thu, Jan 18, 2024 at 05:21:48PM +0000, Mark Brown wrote:
> On Thu, Jan 18, 2024 at 05:58:08PM +0100, Johan Hovold wrote:
> > The default PA gain is set to a pretty high level of 15 dB. Initialise
> > the register to the minimum -3 dB level instead.
> > 
> > This is specifically needed to allow machine drivers to use the lowest
> > level as a volume limit.
> 
> > @@ -722,7 +722,7 @@ static struct reg_default wsa883x_defaults[] = {
> >  	{ WSA883X_WAVG_PER_6_7, 0x88 },
> >  	{ WSA883X_WAVG_STA, 0x00 },
> >  	{ WSA883X_DRE_CTL_0, 0x70 },
> > -	{ WSA883X_DRE_CTL_1, 0x08 },
> > +	{ WSA883X_DRE_CTL_1, 0x1e },
> 
> This is broken, the register defaults provided to regmap need to
> correspond to whatever the hardware default is since for example a
> register cache sync will not write back any default values (as they
> should already be there in the hardware).  Anything like this would need
> to be done by writes during init.

Bah, thanks for catching that. For some reason this was enough to have
the driver initialise the register at boot at least. I'll set it
explicitly at probe instead.

Johan

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