Mark Brown wrote:
On Thu, Dec 17, 2009 at 09:47:59AM +0100, Michael Trimarchi wrote:
I have a simple question is the general behavior that an alsa device start to drain power when it starts to play sound or start to recording. What happen if there is an external amplifier connect to sound device?
In general any audio component is going to draw more power if there is a signal going through it than if it's idle. This is true regardless of how the audio subsystem is split in terms of physical chips.
What are you trying to find out here?
As reported by the datasheet the LM4853 has a bias circuitry shutdown. This shutdown function is activated by applying a logic high to the SHUTDOWN pin. This pin as command by the
static int lm4853_event(struct snd_soc_dapm_widget *w, struct snd_kcontrol *k, int event)
in gta02. I don't put any debug stuff there but I suppose if I open the device with and asound.conf that set the value to true of the Stereo Out this event is called. Is it right?
Michael