Re: [alsa-devel] Power management state flow in ALSA

At Wed, 30 May 2007 11:52:31 +0530, Nobin Mathew wrote:

I am having a doubt regarding ALSA power management.

My understanding of APM suspend() is like this.

Freeze the ALSA apps

Call ALSA driver suspend ()

in the ALSA suspend() function it saves the current state of substream and changes the state of substream to SUSPENDED.

My understanding of APM resume() is like this

Call ALSA driver resume ()

Activate the ALSA apps

In ALSA resume function it restores the saved state of substream.

So my question is when ALSA app will get to know the SUSPENDED state of substream.???

When issuing any syscalls. Then you'll get ESTRPIPE error, which indicitaes the stream is in the SUSPEND state.

Takashi