[PATCH] ASoC: Put LM4853 under DAPM control on GTA02

Mark Brown broonie at opensource.wolfsonmicro.com
Tue Mar 3 13:16:00 CET 2009

On Tue, Mar 03, 2009 at 11:31:13AM +0000, Andy Green wrote:

> I'm thinking about Vref driver impedence for example, unless I am
> suffering from false memory syndrome this is managed as I described,
> such that we are at 500K impedence when using only analogue paths.

The behaviour there is identical before and after this patch?  This is
something I want to improve, though the benefit is relatively small so
it's not bubbled up to the top of my priority list yet.

The only thing this is changing is what gets to make the decision about
powering up the amplifier and when exactly that happens, if there are
other issues (which you haven't reported!) it's not going to affect them.

> | The handling of the digital streams provides automatic power managment
> | for the DACs and ADCs so that their paths aren't powered when they
> | aren't in use.

> How does the power management of the amp improve by DAPM then, just the
> sequencing during suspend and resume?

The sequencing is improved in general (and will be able to benefit from
further improvements in the sequencing as they happen) and the amp power
state is now managed automatically so it'll be powered off when not in
use without manual intervention from applications (which is especially
useful for the digital paths).

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