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.

Takashi