[alsa-devel] Power management state flow in ALSA
tiwai at suse.de
Wed May 30 11:55:34 CEST 2007
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.
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