linux-kernel - Re: Nokia N900 headset detection & MIC Bias + TVOUT

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: <20170109192201.l3mkro3epzf2ns27@sirena.org.uk>
Date:   Mon, 9 Jan 2017 19:22:01 +0000
From:   Mark Brown <broonie@...nel.org>
To:     Pali Rohár <pali.rohar@...il.com>
Cc:     Tony Lindgren <tony@...mide.com>,
        Peter Ujfalusi <peter.ujfalusi@...com>,
        Jarkko Nikula <jarkko.nikula@...mer.com>,
        Liam Girdwood <lgirdwood@...il.com>,
        Lars-Peter Clausen <lars@...afoo.de>,
        Aaro Koskinen <aaro.koskinen@....fi>,
        Nishanth Menon <nm@...com>, Sebastian Reichel <sre@...nel.org>,
        Pavel Machek <pavel@....cz>,
        Ivaylo Dimitrov <ivo.g.dimitrov.75@...il.com>,
        joerg Reisenweber <joerg@...nmoko.org>,
        linux-omap@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: Nokia N900 headset detection & MIC Bias + TVOUT

On Mon, Jan 09, 2017 at 02:13:17PM +0100, Pali Rohár wrote:

> So... can I call snd_soc_dapm_mutex_lock(dapm) at function startup,
> start doing cable detection and when needed call this?

> snd_soc_dapm_enable_pin_unlocked(dapm, "HS Mic");
> snd_soc_dapm_sync_unlocked(dapm);

> And at the end of function revert back "HS Mic" pin status and call
> snd_soc_dapm_mutex_unlock(dapm)?

You shouldn't need to lock I'd expect, and you'll want to sync at any
point where you need an actual change.  Note that if something holds the
microphone bias on (like something using the microphone) separately then
that'll take effect so if you really need things to get turned off then
that won't work but you probably have trouble anyway in that situation.

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