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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Thu, 18 Jan 2024 17:21:48 +0000
From: Mark Brown <broonie@...nel.org>
To: Johan Hovold <johan+linaro@...nel.org>
Cc: 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 05:58:08PM +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.

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)