[PATCH] ASoC: SOF: add mutex to protect the dsp_power_state access

[Kai Vehmanen]

From: Keyon Jie <yang.jie at linux.intel.com>

There could be more than one thread read/write the dsp_power_state
simultaneously (e.g. hda_dsp_d0i3_work and sof_ipc_tx_message), add a
mutex power_state_access to make sure the access to it is mutually
exclusive.

Signed-off-by: Keyon Jie <yang.jie at linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
Reviewed-by: Bard Liao <bard.liao at intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski at linux.intel.com>
Signed-off-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
---
 sound/soc/sof/core.c     |  1 +
 sound/soc/sof/ops.h      | 11 ++++++++---
 sound/soc/sof/sof-priv.h |  2 ++
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/sound/soc/sof/core.c b/sound/soc/sof/core.c
index adc7c37145d6..2b85ef5d6092 100644
--- a/sound/soc/sof/core.c
+++ b/sound/soc/sof/core.c
@@ -316,6 +316,7 @@ int snd_sof_device_probe(struct device *dev, struct snd_sof_pdata *plat_data)
 	INIT_LIST_HEAD(&sdev->route_list);
 	spin_lock_init(&sdev->ipc_lock);
 	spin_lock_init(&sdev->hw_lock);
+	mutex_init(&sdev->power_state_access);
 
 	if (IS_ENABLED(CONFIG_SND_SOC_SOF_PROBE_WORK_QUEUE))
 		INIT_WORK(&sdev->probe_work, sof_probe_work);
diff --git a/sound/soc/sof/ops.h b/sound/soc/sof/ops.h
index 95e748b36903..4c1f9daaa6e8 100644
--- a/sound/soc/sof/ops.h
+++ b/sound/soc/sof/ops.h
@@ -208,11 +208,16 @@ static inline int
 snd_sof_dsp_set_power_state(struct snd_sof_dev *sdev,
 			    const struct sof_dsp_power_state *target_state)
 {
+	int ret = 0;
+
+	mutex_lock(&sdev->power_state_access);
+
 	if (sof_ops(sdev)->set_power_state)
-		return sof_ops(sdev)->set_power_state(sdev, target_state);
+		ret = sof_ops(sdev)->set_power_state(sdev, target_state);
 
-	/* D0 substate is not supported, do nothing here. */
-	return 0;
+	mutex_unlock(&sdev->power_state_access);
+
+	return ret;
 }
 
 /* debug */
diff --git a/sound/soc/sof/sof-priv.h b/sound/soc/sof/sof-priv.h
index 68da8f797403..28d19fa30614 100644
--- a/sound/soc/sof/sof-priv.h
+++ b/sound/soc/sof/sof-priv.h
@@ -375,6 +375,8 @@ struct snd_sof_dev {
 
 	/* current DSP power state */
 	struct sof_dsp_power_state dsp_power_state;
+	/* mutex to protect the dsp_power_state access */
+	struct mutex power_state_access;
 
 	/* Intended power target of system suspend */
 	enum sof_system_suspend_state system_suspend_target;
-- 
2.29.2