[alsa-devel] [PATCH] ASoC: Use codec mutex in dapm_set_pga()

Mark Brown broonie at opensource.wolfsonmicro.com
Thu Oct 1 14:08:14 CEST 2009

On Thu, Oct 01, 2009 at 02:01:09PM +0300, Eero Nurkkala wrote:

> I still think the described scenario can happen. Or could
> you point where the mutex is taken earlier? If it was,
> I would've deadlocked every time....Maybe I'm missing
> some info.

Any of the control paths down from user space should be taking it.

> BTW, what's the reasoning for codec mutex anyway?

It protects all the data on the card - we've got a lot of
read/modify/write cycles going on, plus things like the power state
transitions which need to be run single threaded otherwise they'll get
therribly confused.  We could do something finer grained but it's never
been an issue.

More information about the Alsa-devel mailing list