[alsa-devel] question on alsa's kernel API concerning snd_power_change_state()

Takashi Iwai tiwai at suse.de
Thu Nov 24 09:55:38 CET 2011

At Thu, 24 Nov 2011 09:28:02 +0100,
Oliver Neukum wrote:
> Hi,
> if this function has been used to tell the sound core that a device
> is in a powersave mode, will the soundcore allow user space to open it?

Yes.  Some operations (typically ioctl, read, write) are blocked when
the mode is set to D3 until snd_power_change_state(D0) is called.  But
the open itself isn't blocked.


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