ALSA: Get rid of card power_lock

Currently we're taking power_lock at each card component for assuring
the power-up sequence, but it doesn't help anything in the
implementation at the moment: it just serializes unnecessarily the
callers, but it doesn't protect about the power state change itself.
It used to have some usefulness in the early days where we managed the
PM manually.  But now the suspend/resume core procedure is beyond our
hands, and power_lock lost its meaning.

This patch drops the power_lock from allover the places.
There shouldn't be any issues by this change, as it's no helper
regarding the power state change.  Rather we'll get better performance
by removing the serialization; which is the only slight concern of any
behavior change, but it can't be a showstopper, after all.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 7 insertions, 23 deletions

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index cf0433f80067..621142ea9ec6 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -1830,7 +1830,6 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream,
 		add_wait_queue(&to_check->sleep, &wait);
 		snd_pcm_stream_unlock_irq(substream);
 		up_read(&snd_pcm_link_rwsem);
-		snd_power_unlock(card);
 		if (runtime->no_period_wakeup)
 			tout = MAX_SCHEDULE_TIMEOUT;
 		else {
@@ -1842,7 +1841,6 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream,
 			tout = msecs_to_jiffies(tout * 1000);
 		}
 		tout = schedule_timeout_interruptible(tout);
-		snd_power_lock(card);
 		down_read(&snd_pcm_link_rwsem);
 		snd_pcm_stream_lock_irq(substream);
 		remove_wait_queue(&to_check->sleep, &wait);
@@ -2764,11 +2762,16 @@ static int snd_pcm_tstamp(struct snd_pcm_substream *substream, int __user *_arg)
 	return 0;
 }
 		
-static int snd_pcm_common_ioctl(struct file *file,
+static int snd_pcm_common_ioctl1(struct file *file,
 				 struct snd_pcm_substream *substream,
 				 unsigned int cmd, void __user *arg)
 {
 	struct snd_pcm_file *pcm_file = file->private_data;
+	int res;
+
+	res = snd_power_wait(substream->pcm->card, SNDRV_CTL_POWER_D0);
+	if (res < 0)
+		return res;
 
 	switch (cmd) {
 	case SNDRV_PCM_IOCTL_PVERSION:
@@ -2846,21 +2849,6 @@ static int snd_pcm_common_ioctl(struct file *file,
 	return -ENOTTY;
 }
 
-static int snd_pcm_common_ioctl1(struct file *file,
-				 struct snd_pcm_substream *substream,
-				 unsigned int cmd, void __user *arg)
-{
-	struct snd_card *card = substream->pcm->card;
-	int res;
-
-	snd_power_lock(card);
-	res = snd_power_wait(card, SNDRV_CTL_POWER_D0);
-	if (res >= 0)
-		res = snd_pcm_common_ioctl(file, substream, cmd, arg);
-	snd_power_unlock(card);
-	return res;
-}
-
 static int snd_pcm_playback_ioctl1(struct file *file,
 				   struct snd_pcm_substream *substream,
 				   unsigned int cmd, void __user *arg)
@@ -3064,7 +3052,6 @@ int snd_pcm_kernel_ioctl(struct snd_pcm_substream *substream,
 {
 	snd_pcm_uframes_t *frames = arg;
 	snd_pcm_sframes_t result;
-	int err;
 	
 	switch (cmd) {
 	case SNDRV_PCM_IOCTL_FORWARD:
@@ -3084,10 +3071,7 @@ int snd_pcm_kernel_ioctl(struct snd_pcm_substream *substream,
 	case SNDRV_PCM_IOCTL_START:
 		return snd_pcm_start_lock_irq(substream);
 	case SNDRV_PCM_IOCTL_DRAIN:
-		snd_power_lock(substream->pcm->card);
-		err = snd_pcm_drain(substream, NULL);
-		snd_power_unlock(substream->pcm->card);
-		return err;
+		return snd_pcm_drain(substream, NULL);
 	case SNDRV_PCM_IOCTL_DROP:
 		return snd_pcm_drop(substream);
 	case SNDRV_PCM_IOCTL_DELAY: