ALSA: cs5535audio: turn off PCM properly if closing the audio device

As per <http://dev.laptop.org/ticket/1420>, we need to properly turn off
the PCM if we're closing the device in order to save power.  This also
causes the MIC led to turn off properly.
Signed-off-by: Jaya Kumar <jayakumar.lkml@gmail.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/cs5535audio/cs5535audio.c

@@ -159,7 +159,8 @@ static int __devinit snd_cs5535audio_mixer(struct cs5535audio *cs5535au)
 		return err;
 
 	memset(&ac97, 0, sizeof(ac97));
-	ac97.scaps = AC97_SCAP_AUDIO|AC97_SCAP_SKIP_MODEM;
+	ac97.scaps = AC97_SCAP_AUDIO | AC97_SCAP_SKIP_MODEM
+			| AC97_SCAP_POWER_SAVE;
 	ac97.private_data = cs5535au;
 	ac97.pci = cs5535au->pci;
 

sound/pci/cs5535audio/cs5535audio.h

@@ -78,6 +78,7 @@ struct cs5535audio_dma {
 	unsigned int buf_addr, buf_bytes;
 	unsigned int period_bytes, periods;
 	u32 saved_prd;
+	int pcm_open_flag;
 };
 
 struct cs5535audio {

sound/pci/cs5535audio/cs5535audio_pcm.c

@@ -260,6 +260,9 @@ static int snd_cs5535audio_hw_params(struct snd_pcm_substream *substream,
 	err = cs5535audio_build_dma_packets(cs5535au, dma, substream,
 					    params_periods(hw_params),
 					    params_period_bytes(hw_params));
+	if (!err)
+		dma->pcm_open_flag = 1;
+
 	return err;
 }
 
@@ -268,6 +271,15 @@ static int snd_cs5535audio_hw_free(struct snd_pcm_substream *substream)
 	struct cs5535audio *cs5535au = snd_pcm_substream_chip(substream);
 	struct cs5535audio_dma *dma = substream->runtime->private_data;
 
+	if (dma->pcm_open_flag) {
+		if (substream == cs5535au->playback_substream)
+			snd_ac97_update_power(cs5535au->ac97,
+					AC97_PCM_FRONT_DAC_RATE, 0);
+		else
+			snd_ac97_update_power(cs5535au->ac97,
+					AC97_PCM_LR_ADC_RATE, 0);
+		dma->pcm_open_flag = 0;
+	}
 	cs5535audio_clear_dma_packets(cs5535au, dma, substream);
 	return snd_pcm_lib_free_pages(substream);
 }