question on alsa's kernel API concerning snd_power_change

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* question on alsa's kernel API concerning snd_power_change_state()
@ 2011-11-24  8:28 Oliver Neukum
  2011-11-24  8:55 ` Takashi Iwai
  0 siblings, 1 reply; 2+ messages in thread
From: Oliver Neukum @ 2011-11-24  8:28 UTC (permalink / raw)
  To: alsa-devel; +Cc: Takashi Iwai, Amit Nagal

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?

	Regards
		Oliver

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: question on alsa's kernel API concerning snd_power_change_state()
  2011-11-24  8:28 question on alsa's kernel API concerning snd_power_change_state() Oliver Neukum
@ 2011-11-24  8:55 ` Takashi Iwai
  0 siblings, 0 replies; 2+ messages in thread
From: Takashi Iwai @ 2011-11-24  8:55 UTC (permalink / raw)
  To: Oliver Neukum; +Cc: alsa-devel, Amit Nagal

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

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2011-11-24  8:55 ` Takashi Iwai

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