linux-kernel - Re: [PATCH v2 3/7] ASoC: pcm512x: Change register default to match actual content after reset

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]

Message-ID: <20150128191217.GF21293@sirena.org.uk>
Date:	Wed, 28 Jan 2015 19:12:17 +0000
From:	Mark Brown <broonie@...nel.org>
To:	Peter Rosin <peda@...ator.liu.se>
Cc:	alsa-devel@...a-project.org, Peter Rosin <peda@...ntia.se>,
	Rob Herring <robh+dt@...nel.org>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.de>,
	Liam Girdwood <lgirdwood@...il.com>,
	Clemens Ladisch <clemens@...isch.de>,
	Lars-Peter Clausen <lars@...afoo.de>,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 3/7] ASoC: pcm512x: Change register default to match
 actual content after reset

On Wed, Jan 28, 2015 at 03:16:08PM +0100, Peter Rosin wrote:

> @@ -78,7 +78,7 @@ static const struct reg_default pcm512x_reg_defaults[] = {
>  	{ PCM512x_DIGITAL_VOLUME_2,  0x30 },
>  	{ PCM512x_DIGITAL_VOLUME_3,  0x30 },
>  	{ PCM512x_DIGITAL_MUTE_1,    0x22 },
> -	{ PCM512x_DIGITAL_MUTE_2,    0x00 },
> +	{ PCM512x_DIGITAL_MUTE_2,    0x02 },

The datasheet claims these have undefined values as reserved bits - what
would be a more robust change here would be to remove the register
default entirely so that we take the value the hardware has, giving
robustness against any hardware revisions.  Of course the device has
rather a lot of such reserved bits which is unfortunate.

Download attachment "signature.asc" of type "application/pgp-signature" (474 bytes)