[PATCH] ASoC: core: unregister clients and machine drivers in .shutdown

[Kai Vehmanen]

From: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>

On a platform shutdown, the expectation for most drivers is that
userspace tasks will release all resources. When those sequences do
not complete, it can be the case that PCM devices exposed by ALSA
cards are used *after* the DSP shutdown completes, leading to a
platform hang.

When the clients and machine drivers provide an _unregister callback,
let's invoke it in the shutdown sequence.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
Signed-off-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
---
 sound/soc/sof/core.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/sound/soc/sof/core.c b/sound/soc/sof/core.c
index d99ecbb4282d..2a35d8ddf43e 100644
--- a/sound/soc/sof/core.c
+++ b/sound/soc/sof/core.c
@@ -463,10 +463,19 @@ EXPORT_SYMBOL(snd_sof_device_remove);
 int snd_sof_device_shutdown(struct device *dev)
 {
 	struct snd_sof_dev *sdev = dev_get_drvdata(dev);
+	struct snd_sof_pdata *pdata = sdev->pdata;
 
 	if (IS_ENABLED(CONFIG_SND_SOC_SOF_PROBE_WORK_QUEUE))
 		cancel_work_sync(&sdev->probe_work);
 
+	/*
+	 * make sure clients and machine driver(s) are unregistered to force
+	 * all userspace devices to be closed prior to the DSP shutdown sequence
+	 */
+	sof_unregister_clients(sdev);
+
+	snd_sof_machine_unregister(sdev, pdata);
+
 	if (sdev->fw_state == SOF_FW_BOOT_COMPLETE)
 		return snd_sof_shutdown(sdev);
 

base-commit: f7d344a2bd5ec81fbd1ce76928fd059e57ec9bea
-- 
2.35.1