[PATCH 2/8] ASoC: SOF: core: harden shutdown helper

[Pierre-Louis Bossart]

When the probe is handled in a workqueue, we must use
cancel_work_sync() in the shutdown helper to avoid possible race
conditions.

We must also take care of possible errors happening in a probe
workqueue or during pm_runtime resume (called e.g. before shutdown for
PCI devices). We should really only try to access hardware registers
and initiate IPCs if the DSP is fully booted.

Fixes: daff7f1478e12 ("ASoC: SOF: add snd_sof_device_shutdown() helper for shutdown")
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Reviewed-by: Libin Yang <libin.yang at intel.com>
---
 sound/soc/sof/core.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/sound/soc/sof/core.c b/sound/soc/sof/core.c
index 495295a34c3a..7005353602c4 100644
--- a/sound/soc/sof/core.c
+++ b/sound/soc/sof/core.c
@@ -400,7 +400,13 @@ int snd_sof_device_shutdown(struct device *dev)
 {
 	struct snd_sof_dev *sdev = dev_get_drvdata(dev);
 
-	return snd_sof_shutdown(sdev);
+	if (IS_ENABLED(CONFIG_SND_SOC_SOF_PROBE_WORK_QUEUE))
+		cancel_work_sync(&sdev->probe_work);
+
+	if (sdev->fw_state == SOF_FW_BOOT_COMPLETE)
+		return snd_sof_shutdown(sdev);
+
+	return 0;
 }
 EXPORT_SYMBOL(snd_sof_device_shutdown);
 
-- 
2.25.1