ASoC: rt1316-sdw: enable pm_runtime in probe, keep status as 'suspended'

This patch suggests enabling pm_runtime during the probe, but marking the
device as 'active' only after it is enumerated. That will force a
dependency between the card and the codec, pm_runtime_get_sync() will
have to wait for the codec device to resume and hence implicitly wait
for the enumeration/initialization to be completed. In the nominal
case where the codec device is already active the get_sync() would
only perform a ref-count increase.

The changes are directly inspired by RT711 and RT711-sdca changes.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20230802153629.53576-13-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/rt1316-sdw.c

@@ -277,20 +277,11 @@ static int rt1316_io_init(struct device *dev, struct sdw_slave *slave)
 		regcache_cache_bypass(rt1316->regmap, true);
 	} else {
 		/*
-		 * PM runtime is only enabled when a Slave reports as Attached
+		 *  PM runtime status is marked as 'active' only when a Slave reports as Attached
 		 */
 
-		/* set autosuspend parameters */
-		pm_runtime_set_autosuspend_delay(&slave->dev, 3000);
-		pm_runtime_use_autosuspend(&slave->dev);
-
 		/* update count of parent 'active' children */
 		pm_runtime_set_active(&slave->dev);
-
-		/* make sure the device does not suspend immediately */
-		pm_runtime_mark_last_busy(&slave->dev);
-
-		pm_runtime_enable(&slave->dev);
 	}
 
 	pm_runtime_get_noresume(&slave->dev);
@@ -607,6 +598,9 @@ static int rt1316_sdw_component_probe(struct snd_soc_component *component)
 	rt1316->component = component;
 	rt1316_sdw_parse_dt(rt1316, &rt1316->sdw_slave->dev);
 
+	if (!rt1316->first_hw_init)
+		return 0;
+
 	ret = pm_runtime_resume(component->dev);
 	if (ret < 0 && ret != -EACCES)
 		return ret;
@@ -687,10 +681,27 @@ static int rt1316_sdw_init(struct device *dev, struct regmap *regmap,
 				&soc_component_sdw_rt1316,
 				rt1316_sdw_dai,
 				ARRAY_SIZE(rt1316_sdw_dai));
+	if (ret < 0)
+		return ret;
 
-	dev_dbg(&slave->dev, "%s\n", __func__);
+	/* set autosuspend parameters */
+	pm_runtime_set_autosuspend_delay(dev, 3000);
+	pm_runtime_use_autosuspend(dev);
 
-	return ret;
+	/* make sure the device does not suspend immediately */
+	pm_runtime_mark_last_busy(dev);
+
+	pm_runtime_enable(dev);
+
+	/* important note: the device is NOT tagged as 'active' and will remain
+	 * 'suspended' until the hardware is enumerated/initialized. This is required
+	 * to make sure the ASoC framework use of pm_runtime_get_sync() does not silently
+	 * fail with -EACCESS because of race conditions between card creation and enumeration
+	 */
+
+	dev_dbg(dev, "%s\n", __func__);
+
+	return 0;
 }
 
 static int rt1316_sdw_probe(struct sdw_slave *slave,
@@ -708,10 +719,7 @@ static int rt1316_sdw_probe(struct sdw_slave *slave,
 
 static int rt1316_sdw_remove(struct sdw_slave *slave)
 {
-	struct rt1316_sdw_priv *rt1316 = dev_get_drvdata(&slave->dev);
-
-	if (rt1316->first_hw_init)
-		pm_runtime_disable(&slave->dev);
+	pm_runtime_disable(&slave->dev);
 
 	return 0;
 }