ASoC: rt700: 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/20230802153629.53576-7-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/codecs/rt700-sdw.c b/sound/soc/codecs/rt700-sdw.c
index 53e7973..52c33d5 100644 (file)
--- a/sound/soc/codecs/rt700-sdw.c
+++ b/sound/soc/codecs/rt700-sdw.c
@@ -464,8 +464,7 @@ static int rt700_sdw_remove(struct sdw_slave *slave)
                cancel_delayed_work_sync(&rt700->jack_btn_check_work);
        }
 
-       if (rt700->first_hw_init)
-               pm_runtime_disable(&slave->dev);
+       pm_runtime_disable(&slave->dev);
 
        return 0;
 }

diff --git a/sound/soc/codecs/rt700.c b/sound/soc/codecs/rt700.c
index b774349..0ebf344 100644 (file)
--- a/sound/soc/codecs/rt700.c
+++ b/sound/soc/codecs/rt700.c
@@ -320,6 +320,10 @@ static int rt700_set_jack_detect(struct snd_soc_component *component,
 
        rt700->hs_jack = hs_jack;
 
+       /* we can only resume if the device was initialized at least once */
+       if (!rt700->first_hw_init)
+               return 0;
+
        ret = pm_runtime_resume_and_get(component->dev);
        if (ret < 0) {
                if (ret != -EACCES) {
@@ -823,6 +827,9 @@ static int rt700_probe(struct snd_soc_component *component)
 
        rt700->component = component;
 
+       if (!rt700->first_hw_init)
+               return 0;
+
        ret = pm_runtime_resume(component->dev);
        if (ret < 0 && ret != -EACCES)
                return ret;
@@ -1119,10 +1126,26 @@ int rt700_init(struct device *dev, struct regmap *sdw_regmap,
                                &soc_codec_dev_rt700,
                                rt700_dai,
                                ARRAY_SIZE(rt700_dai));
+       if (ret < 0)
+               return ret;
+
+       /* set autosuspend parameters */
+       pm_runtime_set_autosuspend_delay(dev, 3000);
+       pm_runtime_use_autosuspend(dev);
+
+       /* 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(&slave->dev, "%s\n", __func__);
 
-       return ret;
+       return 0;
 }
 
 int rt700_io_init(struct device *dev, struct sdw_slave *slave)
@@ -1141,20 +1164,10 @@ int rt700_io_init(struct device *dev, struct sdw_slave *slave)
        /*
         * PM runtime is only enabled when a Slave reports as Attached
         */
-       if (!rt700->first_hw_init) {
-               /* set autosuspend parameters */
-               pm_runtime_set_autosuspend_delay(&slave->dev, 3000);
-               pm_runtime_use_autosuspend(&slave->dev);
-
-               /* update count of parent 'active' children */
+       if (!rt700->first_hw_init)
+               /* PM runtime status is marked as 'active' only when a Slave reports as Attached */
                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);
 
        /* reset */