From 6dbe662874ba08585eaf732d126762c25ac8e3f7 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 27 Jun 2006 18:28:53 +0200 Subject: [ALSA] Add experimental support of aggressive AC97 power-saving mode Added CONFIG_SND_AC97_POWER_SAVE kernel config to enable the support of aggressive AC97 power-saving mode. In this mode, the AC97 powerdown register bits are dynamically controlled at each open/close of PCM streams. The mode is activated via power_save option for snd-ac97-codec driver. As default it's off. It can be turned on/off on the fly via sysfs, too. Signed-off-by: Takashi Iwai Signed-off-by: Jaroslav Kysela --- sound/pci/via82xx.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'sound/pci/via82xx.c') diff --git a/sound/pci/via82xx.c b/sound/pci/via82xx.c index 08da9234efb..2c23a665c3e 100644 --- a/sound/pci/via82xx.c +++ b/sound/pci/via82xx.c @@ -1277,7 +1277,18 @@ static int snd_via82xx_pcm_close(struct snd_pcm_substream *substream) if (! ratep->used) ratep->rate = 0; spin_unlock_irq(&ratep->lock); - + if (! ratep->rate) { + if (! viadev->direction) { + snd_ac97_update_power(chip->ac97, + AC97_PCM_FRONT_DAC_RATE, 0); + snd_ac97_update_power(chip->ac97, + AC97_PCM_SURR_DAC_RATE, 0); + snd_ac97_update_power(chip->ac97, + AC97_PCM_LFE_DAC_RATE, 0); + } else + snd_ac97_update_power(chip->ac97, + AC97_PCM_LR_ADC_RATE, 0); + } viadev->substream = NULL; return 0; } -- cgit v1.2.3