[alsa-devel] question on snd_power_change_state()
Hi,
will calling snd_power_change_state() reset all mixer settings?
Regards Oliver
At Fri, 11 Mar 2011 13:12:17 +0100, Oliver Neukum wrote:
Hi,
will calling snd_power_change_state() reset all mixer settings?
No, it's a simple inline function defined in include/sound/core.h.
static inline void snd_power_change_state(struct snd_card *card, unsigned int state) { card->power_state = state; wake_up(&card->power_sleep); }
It's present mostly for historical reasons.
Takashi
Am Freitag, 11. März 2011, 13:15:28 schrieb Takashi Iwai:
At Fri, 11 Mar 2011 13:12:17 +0100, Oliver Neukum wrote:
Hi,
will calling snd_power_change_state() reset all mixer settings?
No, it's a simple inline function defined in include/sound/core.h.
static inline void snd_power_change_state(struct snd_card *card, unsigned int state) { card->power_state = state; wake_up(&card->power_sleep); }
It's present mostly for historical reasons.
Is there a helper that will do that?
Regards Oliver
At Fri, 11 Mar 2011 13:20:46 +0100, Oliver Neukum wrote:
Am Freitag, 11. März 2011, 13:15:28 schrieb Takashi Iwai:
At Fri, 11 Mar 2011 13:12:17 +0100, Oliver Neukum wrote:
Hi,
will calling snd_power_change_state() reset all mixer settings?
No, it's a simple inline function defined in include/sound/core.h.
static inline void snd_power_change_state(struct snd_card *card, unsigned int state) { card->power_state = state; wake_up(&card->power_sleep); }
It's present mostly for historical reasons.
Is there a helper that will do that?
A helper for what?
Takashi
Am Freitag, 11. März 2011, 13:34:17 schrieb Takashi Iwai:
At Fri, 11 Mar 2011 13:20:46 +0100, Oliver Neukum wrote:
Am Freitag, 11. März 2011, 13:15:28 schrieb Takashi Iwai:
At Fri, 11 Mar 2011 13:12:17 +0100, Oliver Neukum wrote:
Hi,
will calling snd_power_change_state() reset all mixer settings?
No, it's a simple inline function defined in include/sound/core.h.
static inline void snd_power_change_state(struct snd_card *card, unsigned int state) { card->power_state = state; wake_up(&card->power_sleep); }
It's present mostly for historical reasons.
Is there a helper that will do that?
A helper for what?
A helper for restoring all mixer settings that a device has lost due to a loss of power.
Regards Oliver
At Fri, 11 Mar 2011 13:42:44 +0100, Oliver Neukum wrote:
Am Freitag, 11. März 2011, 13:34:17 schrieb Takashi Iwai:
At Fri, 11 Mar 2011 13:20:46 +0100, Oliver Neukum wrote:
Am Freitag, 11. März 2011, 13:15:28 schrieb Takashi Iwai:
At Fri, 11 Mar 2011 13:12:17 +0100, Oliver Neukum wrote:
Hi,
will calling snd_power_change_state() reset all mixer settings?
No, it's a simple inline function defined in include/sound/core.h.
static inline void snd_power_change_state(struct snd_card *card, unsigned int state) { card->power_state = state; wake_up(&card->power_sleep); }
It's present mostly for historical reasons.
Is there a helper that will do that?
A helper for what?
A helper for restoring all mixer settings that a device has lost due to a loss of power.
No. It's driver-specific.
Takashi
On Fri, Mar 11, 2011 at 02:13:12PM +0100, Takashi Iwai wrote:
Oliver Neukum wrote:
A helper for restoring all mixer settings that a device has lost due to a loss of power.
No. It's driver-specific.
If you're working within ASoC the register cache code has support for syncing back to hardware.
At Fri, 11 Mar 2011 13:53:13 +0000, Mark Brown wrote:
On Fri, Mar 11, 2011 at 02:13:12PM +0100, Takashi Iwai wrote:
Oliver Neukum wrote:
A helper for restoring all mixer settings that a device has lost due to a loss of power.
No. It's driver-specific.
If you're working within ASoC the register cache code has support for syncing back to hardware.
Right.
But usb-audio has no register (not only it doesn't using ASoC :)
Takashi
participants (3)
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Mark Brown -
Oliver Neukum -
Takashi Iwai