[RFC PATCH v2 1/2] ASoC: refine ASoC hdmi audio suspend/resume

[libin.yang@intel.com]

From: Libin Yang <libin.yang@intel.com>

hdmi_codec_prepare() will trigger hdmi runtime resume, which will set
the bitmask of hdev->addr. And skl_suspend() will clear the bitmask of
HDA_CODEC_IDX_CONTROLLER. HDMI codec idx is not the same as
HDA_CODEC_IDX_CONTROLLER, which means i915 power will not be released
when suspend.

On the other hand, hdmi_codec_prepare() don't need to call
pm_runtime_get_sync() to wake up the audio subsystem (HDMI auido)
for setting the codec registers. Turning display power on with
snd_hdac_display_power() is enough.

Let's use S3 without playback as an example:
hdmi_codec_prepare() invokes the runtime resume of codec =>
  snd_hdac_display_power(bus, hdev->addr, true)
skl runtime resume
skl_suspend() =>
  snd_hdac_display_power(bus, HDA_CODEC_IDX_CONTROLLER, false);

THis means hdev->addr will never release the display power when
suspend.

The new sequence will be:
hdmi_codec_prepare() =>
  snd_hdac_display_power(bus, hdev->addr, true)
  snd_hdac_display_power(bus, hdev->addr, false)
skl runtime resume
skl suspned

Signed-off-by: Libin Yang <libin.yang@intel.com>
---
 sound/soc/codecs/hdac_hdmi.c  | 6 ++++--
 sound/soc/intel/skylake/skl.c | 7 -------
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/sound/soc/codecs/hdac_hdmi.c b/sound/soc/codecs/hdac_hdmi.c
index 3ab2949..782b323 100644
--- a/sound/soc/codecs/hdac_hdmi.c
+++ b/sound/soc/codecs/hdac_hdmi.c
@@ -1895,7 +1895,7 @@ static int hdmi_codec_prepare(struct device *dev)
 {
 	struct hdac_device *hdev = dev_to_hdac_dev(dev);
 
-	pm_runtime_get_sync(&hdev->dev);
+	snd_hdac_display_power(hdev->bus, hdev->addr, true);
 
 	/*
 	 * Power down afg.
@@ -1906,6 +1906,7 @@ static int hdmi_codec_prepare(struct device *dev)
 	 */
 	snd_hdac_codec_read(hdev, hdev->afg, 0,	AC_VERB_SET_POWER_STATE,
 							AC_PWRST_D3);
+	snd_hdac_display_power(hdev->bus, hdev->addr, false);
 
 	return 0;
 }
@@ -1915,6 +1916,7 @@ static void hdmi_codec_complete(struct device *dev)
 	struct hdac_device *hdev = dev_to_hdac_dev(dev);
 	struct hdac_hdmi_priv *hdmi = hdev_to_hdmi_priv(hdev);
 
+	snd_hdac_display_power(hdev->bus, hdev->addr, true);
 	/* Power up afg */
 	snd_hdac_codec_read(hdev, hdev->afg, 0,	AC_VERB_SET_POWER_STATE,
 							AC_PWRST_D0);
@@ -1930,7 +1932,7 @@ static void hdmi_codec_complete(struct device *dev)
 	 */
 	hdac_hdmi_present_sense_all_pins(hdev, hdmi, false);
 
-	pm_runtime_put_sync(&hdev->dev);
+	snd_hdac_display_power(hdev->bus, hdev->addr, false);
 }
 #else
 #define hdmi_codec_prepare NULL
diff --git a/sound/soc/intel/skylake/skl.c b/sound/soc/intel/skylake/skl.c
index 60c9483..89f4d66 100644
--- a/sound/soc/intel/skylake/skl.c
+++ b/sound/soc/intel/skylake/skl.c
@@ -336,9 +336,6 @@ static int skl_suspend(struct device *dev)
 		skl->skl_sst->fw_loaded = false;
 	}
 
-	if (IS_ENABLED(CONFIG_SND_SOC_HDAC_HDMI))
-		snd_hdac_display_power(bus, HDA_CODEC_IDX_CONTROLLER, false);
-
 	return 0;
 }
 
@@ -350,10 +347,6 @@ static int skl_resume(struct device *dev)
 	struct hdac_ext_link *hlink = NULL;
 	int ret;
 
-	/* Turned OFF in HDMI codec driver after codec reconfiguration */
-	if (IS_ENABLED(CONFIG_SND_SOC_HDAC_HDMI))
-		snd_hdac_display_power(bus, HDA_CODEC_IDX_CONTROLLER, true);
-
 	/*
 	 * resume only when we are not in suspend active, otherwise need to
 	 * restore the device
-- 
2.7.4