ALSA: hda - Use standard runtime PM for codec power-save control

Like the previous transition of suspend/resume, now move the
power-save code to the standard runtime PM.  As usual for runtime PM,
it's a bit tricky, but this simplified codes a lot in the end.

For keeping the usage compatibility, power_save module option still
controls the whole power-saving behavior on all codecs.  The value is
translated to pm_runtime_*_autosuspend() and pm_runtime_allow() /
pm_runtime_forbid() calls.

snd_hda_power_up() and snd_hda_power_down() are translated to
pm_runtime_get_sync() and pm_runtime_put_autosuspend(), respectively.
Since we can do call pm_runtime_get_sync() more reliably, the sync
version is used always and snd_hda_power_up_d3wait() is dropped.
Another slight difference is that snd_hda_power_up()/down() don't call
runtime_pm code during the suspend/resume transition phase.  Calling
them there isn't safe unlike our own code, resulted in unexpected
behavior (endless wakeups).

The hda_power_count tracepoint was removed, as it doesn't match well
with the new code.

Last but not least, we need to set ignore_children flag in the parent
dev.power field so that the runtime PM of the controller chip won't
get confused.  The notification is still done in the bus pm_notify
callback.  We'll get rid of this hack in the later patch.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_codec.h

@@ -372,17 +372,12 @@ struct hda_codec {
 	unsigned int dp_mst:1; /* support DP1.2 Multi-stream transport */
 	unsigned int dump_coef:1; /* dump processing coefs in codec proc file */
 #ifdef CONFIG_PM
-	unsigned int power_on :1;	/* current (global) power-state */
 	unsigned int d3_stop_clk:1;	/* support D3 operation without BCLK */
 	unsigned int pm_up_notified:1;	/* PM notified to controller */
-	unsigned int in_pm:1;		/* suspend/resume being performed */
-	int power_transition;	/* power-state in transition */
-	int power_count;	/* current (global) power refcount */
-	struct delayed_work power_work; /* delayed task for powerdown */
+	atomic_t in_pm;		/* suspend/resume being performed */
 	unsigned long power_on_acct;
 	unsigned long power_off_acct;
 	unsigned long power_jiffies;
-	spinlock_t power_lock;
 #endif
 
 	/* filter the requested power state per nid */
@@ -595,64 +590,16 @@ const char *snd_hda_get_jack_location(u32 cfg);
  * power saving
  */
 #ifdef CONFIG_PM
-void snd_hda_power_save(struct hda_codec *codec, int delta, bool d3wait);
+void snd_hda_power_up(struct hda_codec *codec);
+void snd_hda_power_down(struct hda_codec *codec);
+void snd_hda_power_sync(struct hda_codec *codec);
 void snd_hda_update_power_acct(struct hda_codec *codec);
 #else
-static inline void snd_hda_power_save(struct hda_codec *codec, int delta,
-				      bool d3wait) {}
+static inline void snd_hda_power_up(struct hda_codec *codec) {}
+static inline void snd_hda_power_down(struct hda_codec *codec) {}
+static inline void snd_hda_power_sync(struct hda_codec *codec) {}
 #endif
 
-/**
- * snd_hda_power_up - Power-up the codec
- * @codec: HD-audio codec
- *
- * Increment the power-up counter and power up the hardware really when
- * not turned on yet.
- */
-static inline void snd_hda_power_up(struct hda_codec *codec)
-{
-	snd_hda_power_save(codec, 1, false);
-}
-
-/**
- * snd_hda_power_up_d3wait - Power-up the codec after waiting for any pending
- *   D3 transition to complete.  This differs from snd_hda_power_up() when
- *   power_transition == -1.  snd_hda_power_up sees this case as a nop,
- *   snd_hda_power_up_d3wait waits for the D3 transition to complete then powers
- *   back up.
- * @codec: HD-audio codec
- *
- * Cancel any power down operation hapenning on the work queue, then power up.
- */
-static inline void snd_hda_power_up_d3wait(struct hda_codec *codec)
-{
-	snd_hda_power_save(codec, 1, true);
-}
-
-/**
- * snd_hda_power_down - Power-down the codec
- * @codec: HD-audio codec
- *
- * Decrement the power-up counter and schedules the power-off work if
- * the counter rearches to zero.
- */
-static inline void snd_hda_power_down(struct hda_codec *codec)
-{
-	snd_hda_power_save(codec, -1, false);
-}
-
-/**
- * snd_hda_power_sync - Synchronize the power-save status
- * @codec: HD-audio codec
- *
- * Synchronize the actual power state with the power account;
- * called when power_save parameter is changed
- */
-static inline void snd_hda_power_sync(struct hda_codec *codec)
-{
-	snd_hda_power_save(codec, 0, false);
-}
-
 #ifdef CONFIG_SND_HDA_PATCH_LOADER
 /*
  * patch firmware

sound/pci/hda/hda_controller.c

@@ -836,7 +836,7 @@ static int azx_pcm_open(struct snd_pcm_substream *substream)
 				   buff_step);
 	snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
 				   buff_step);
-	snd_hda_power_up_d3wait(apcm->codec);
+	snd_hda_power_up(apcm->codec);
 	err = hinfo->ops.open(hinfo, apcm->codec, substream);
 	if (err < 0) {
 		azx_release_device(azx_dev);

sound/pci/hda/hda_intel.c

@@ -1087,6 +1087,7 @@ static int azx_free(struct azx *chip)
 		azx_stop_chip(chip);
 	}
 
+	pci->dev.power.ignore_children = 0; /* FIXME */
 	if (chip->irq >= 0)
 		free_irq(chip->irq, (void*)chip);
 	if (chip->msi)
@@ -1796,6 +1797,7 @@ static int azx_probe(struct pci_dev *pci,
 		return err;
 	}
 
+	pci->dev.power.ignore_children = 1; /* FIXME */
 	err = azx_create(card, pci, dev, pci_id->driver_data,
 			 &pci_hda_ops, &chip);
 	if (err < 0)

sound/pci/hda/hda_trace.h

@@ -87,30 +87,6 @@ DEFINE_EVENT(hda_power, hda_power_up,
 	TP_PROTO(struct hda_codec *codec),
 	TP_ARGS(codec)
 );
-
-TRACE_EVENT(hda_power_count,
-	TP_PROTO(struct hda_codec *codec),
-	TP_ARGS(codec),
-	TP_STRUCT__entry(
-		__field( unsigned int, card )
-		__field( unsigned int, addr )
-		__field( int, power_count )
-		__field( int, power_on )
-		__field( int, power_transition )
-	),
-
-	TP_fast_assign(
-		__entry->card = (codec)->bus->card->number;
-		__entry->addr = (codec)->addr;
-		__entry->power_count = (codec)->power_count;
-		__entry->power_on = (codec)->power_on;
-		__entry->power_transition = (codec)->power_transition;
-	),
-
-	TP_printk("[%d:%d] power_count=%d, power_on=%d, power_transition=%d",
-		  __entry->card, __entry->addr, __entry->power_count,
-		  __entry->power_on, __entry->power_transition)
-);
 #endif /* CONFIG_PM */
 
 TRACE_EVENT(hda_unsol_event,