ASoC: rt1308-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/20230802153629.53576-12-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/codecs/rt1308-sdw.c b/sound/soc/codecs/rt1308-sdw.c
index 2c4e533..c98cd7a 100644 (file)
--- a/sound/soc/codecs/rt1308-sdw.c
+++ b/sound/soc/codecs/rt1308-sdw.c
@@ -223,22 +223,12 @@ static int rt1308_io_init(struct device *dev, struct sdw_slave *slave)
                regcache_cache_bypass(rt1308->regmap, true);
 
        /*
-        * 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
         */
-       if (!rt1308->first_hw_init) {
-               /* set autosuspend parameters */
-               pm_runtime_set_autosuspend_delay(&slave->dev, 3000);
-               pm_runtime_use_autosuspend(&slave->dev);
-
+       if (!rt1308->first_hw_init)
                /* 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);
 
        /* sw reset */
@@ -625,6 +615,9 @@ static int rt1308_sdw_component_probe(struct snd_soc_component *component)
        rt1308->component = component;
        rt1308_sdw_parse_dt(rt1308, &rt1308->sdw_slave->dev);
 
+       if (!rt1308->first_hw_init)
+               return 0;
+
        ret = pm_runtime_resume(component->dev);
        if (ret < 0 && ret != -EACCES)
                return ret;
@@ -700,10 +693,27 @@ static int rt1308_sdw_init(struct device *dev, struct regmap *regmap,
                                &soc_component_sdw_rt1308,
                                rt1308_sdw_dai,
                                ARRAY_SIZE(rt1308_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 rt1308_sdw_probe(struct sdw_slave *slave,
@@ -721,10 +731,7 @@ static int rt1308_sdw_probe(struct sdw_slave *slave,
 
 static int rt1308_sdw_remove(struct sdw_slave *slave)
 {
-       struct rt1308_sdw_priv *rt1308 = dev_get_drvdata(&slave->dev);
-
-       if (rt1308->first_hw_init)
-               pm_runtime_disable(&slave->dev);
+       pm_runtime_disable(&slave->dev);
 
        return 0;
 }