CS40L26: Fix race conditions between cl_dsp struct and sysfs accessandroid-15-beta-2_r0.5android-15-beta-2_r0.2android-15-beta-2_r0.1android-gs-raviole-5.10-android15-betaandroid-gs-felix-5.10-android15-betaandroid-gs-bluejay-5.10-android15-beta

Add mutex lock cl_dsp_lock on the following functions:
- cs40l26_cl_dsp_reinit()
- cs40l26_get_num_waves()
- f0_offset_store()
- owt_free_space_show()

Add flush_work to ensure proper synchronization during reset recovery

Bug: 324075191
Test: Primitive vibration with reset no KP
Test: idlcli commands
Test: Alarm, keyboard vibrations
Change-Id: I24cfc6631efcf4ccae64318e8a408facb3a76d4b
Signed-off-by: leonardian <leonardian@google.com>

3 files changed, 49 insertions, 5 deletions

diff --git a/cs40l26/cs40l26-sysfs.c b/cs40l26/cs40l26-sysfs.c
index bb6f3d8..bf1b2da 100644
--- a/cs40l26/cs40l26-sysfs.c
+++ b/cs40l26/cs40l26-sysfs.c
@@ -261,8 +261,14 @@ static ssize_t owt_free_space_show(struct device *dev,
 	if (ret)
 		return ret;
 
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_lock(&cs40l26->cl_dsp_lock);
+#endif
 	ret = cl_dsp_get_reg(cs40l26->dsp, "OWT_SIZE_XM",
 		CL_DSP_XM_UNPACKED_TYPE, CS40L26_VIBEGEN_ALGO_ID, &reg);
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_unlock(&cs40l26->cl_dsp_lock);
+#endif
 	if (ret)
 		goto err_pm;
 
@@ -468,10 +474,15 @@ static ssize_t f0_offset_store(struct device *dev,
 		return ret;
 
 	mutex_lock(&cs40l26->lock);
-
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_lock(&cs40l26->cl_dsp_lock);
+#endif
 	ret = cl_dsp_get_reg(cs40l26->dsp, "F0_OFFSET",
 			CL_DSP_XM_UNPACKED_TYPE, CS40L26_VIBEGEN_ALGO_ID,
 			&reg);
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_unlock(&cs40l26->cl_dsp_lock);
+#endif
 	if (ret)
 		goto err_mutex;
 
@@ -841,9 +852,12 @@ static ssize_t reset_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	if (choice == 0) {
-		cs40l26_make_reset_decision(cs40l26, __func__);
-	} else if (choice == 1) {
+	/*
+	 * Calling flush_work() within sysfs function will cause KP.
+	 * cs40l26_make_reset_decision(cs40l26, __func__);
+	 */
+
+	if (choice == 1) {
 		cs40l26->reset_event = CS40L26_RESET_EVENT_NONEED;
 		cs40l26->reset_count = 0;
 		queue_work(cs40l26->vibe_workqueue, &cs40l26->reset_work);
diff --git a/cs40l26/cs40l26.c b/cs40l26/cs40l26.c
index 4dfdc85..124493a 100644
--- a/cs40l26/cs40l26.c
+++ b/cs40l26/cs40l26.c
@@ -2162,9 +2162,15 @@ int cs40l26_get_num_waves(struct cs40l26_private *cs40l26, u32 *num_waves)
 	int ret;
 	u32 reg, nwaves, nowt;
 
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_lock(&cs40l26->cl_dsp_lock);
+#endif
 	ret = cl_dsp_get_reg(cs40l26->dsp, "NUM_OF_WAVES",
 			CL_DSP_XM_UNPACKED_TYPE,
 			CS40L26_VIBEGEN_ALGO_ID, &reg);
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_unlock(&cs40l26->cl_dsp_lock);
+#endif
 	if (ret)
 		return ret;
 
@@ -2172,8 +2178,14 @@ int cs40l26_get_num_waves(struct cs40l26_private *cs40l26, u32 *num_waves)
 	if (ret)
 		return ret;
 
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_lock(&cs40l26->cl_dsp_lock);
+#endif
 	ret = cl_dsp_get_reg(cs40l26->dsp, "OWT_NUM_OF_WAVES_XM",
 			CL_DSP_XM_UNPACKED_TYPE, CS40L26_VIBEGEN_ALGO_ID, &reg);
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_unlock(&cs40l26->cl_dsp_lock);
+#endif
 	if (ret)
 		return ret;
 
@@ -4410,10 +4422,16 @@ static int cs40l26_cl_dsp_reinit(struct cs40l26_private *cs40l26)
 {
 	int ret;
 
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_lock(&cs40l26->cl_dsp_lock);
+#endif
 	if (cs40l26->dsp) {
 		ret = cl_dsp_destroy(cs40l26->dsp);
 		if (ret) {
 			dev_err(cs40l26->dev, "Failed to destroy DSP struct\n");
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+			mutex_unlock(&cs40l26->cl_dsp_lock);
+#endif
 			return ret;
 		}
 
@@ -4421,6 +4439,9 @@ static int cs40l26_cl_dsp_reinit(struct cs40l26_private *cs40l26)
 	}
 
 	cs40l26->dsp = cl_dsp_create(cs40l26->dev, cs40l26->regmap);
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_unlock(&cs40l26->cl_dsp_lock);
+#endif
 	if (IS_ERR(cs40l26->dsp))
 		return PTR_ERR(cs40l26->dsp);
 
@@ -5077,6 +5098,9 @@ void cs40l26_make_reset_decision(struct cs40l26_private *cs40l26, const char *fu
 	if (trigger) {
 		dev_info(dev, "Queue reset work after %s", func);
 		queue_work(cs40l26->vibe_workqueue, &cs40l26->reset_work);
+
+		/* Wait for reset to finish */
+		flush_work(&cs40l26->reset_work);
 	} else
 		dev_info(dev, "Reset event: %d. Skip this trigger from %s.", cs40l26->reset_event,
 			 func);
@@ -5090,6 +5114,9 @@ int cs40l26_probe(struct cs40l26_private *cs40l26,
 	int ret;
 
 	mutex_init(&cs40l26->lock);
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_init(&cs40l26->cl_dsp_lock);
+#endif
 
 	cs40l26->vibe_workqueue = alloc_ordered_workqueue("vibe_workqueue",
 			WQ_HIGHPRI);
@@ -5239,7 +5266,9 @@ int cs40l26_remove(struct cs40l26_private *cs40l26)
 
 	disable_irq(cs40l26->irq);
 	mutex_destroy(&cs40l26->lock);
-
+#if IS_ENABLED(CONFIG_GOOG_CUST)
+	mutex_destroy(&cs40l26->cl_dsp_lock);
+#endif
 
 	if (cs40l26->pm_ready)
 		cs40l26_pm_runtime_teardown(cs40l26);
diff --git a/cs40l26/cs40l26.h b/cs40l26/cs40l26.h
index 13f24db..99e1915 100644
--- a/cs40l26/cs40l26.h
+++ b/cs40l26/cs40l26.h
@@ -1588,6 +1588,7 @@ struct cs40l26_private {
 	struct cl_dsp_debugfs *cl_dsp_db;
 #endif
 #if IS_ENABLED(CONFIG_GOOG_CUST)
+	struct mutex cl_dsp_lock;
 	struct work_struct reset_work;
 	enum cs40l26_reset_event reset_event;
 	u8 reset_count;