touch: fts: add mutex to protect offload report

When the release_all_touches and offload_report run at the same time,
it may cause the input report conflict before input sync.

bug: 190460965
Test: flash boot.img and vendor_boot.img.

Signed-off-by: davidycchen <davidycchen@google.com>
Change-Id: I35e5d296a762629e64d0851f5336b7de604f8e86

2 files changed, 23 insertions, 5 deletions

diff --git a/fts.c b/fts.c
index e2cf7be..5fbc576 100644
--- a/fts.c
+++ b/fts.c
@@ -163,6 +163,8 @@ void release_all_touches(struct fts_ts_info *info)
 	unsigned int type = MT_TOOL_FINGER;
 	int i;
 
+	mutex_lock(&info->input_report_mutex);
+
 	for (i = 0; i < TOUCH_ID_MAX; i++) {
 #ifdef STYLUS_MODE
 		if (test_bit(i, &info->stylus_id))
@@ -183,6 +185,9 @@ void release_all_touches(struct fts_ts_info *info)
 	}
 	input_report_key(info->input_dev, BTN_TOUCH, 0);
 	input_sync(info->input_dev);
+
+	mutex_unlock(&info->input_report_mutex);
+
 	info->touch_id = 0;
 	info->palm_touch_mask = 0;
 	info->grip_touch_mask = 0;
@@ -191,7 +196,6 @@ void release_all_touches(struct fts_ts_info *info)
 #endif
 }
 
-
 /**
   * @defgroup file_nodes Driver File Nodes
   * Driver publish a series of file nodes used to provide several utilities
@@ -3003,6 +3007,8 @@ static bool fts_enter_pointer_event_handler(struct fts_ts_info *info, unsigned
 	if (!info->resume_bit)
 		goto no_report;
 
+	mutex_lock(&info->input_report_mutex);
+
 	touchType = event[1] & 0x0F;
 	touchId = (event[1] & 0xF0) >> 4;
 
@@ -3087,6 +3093,7 @@ static bool fts_enter_pointer_event_handler(struct fts_ts_info *info, unsigned
 		break;
 
 	default:
+		mutex_unlock(&info->input_report_mutex);
 		pr_err("%s : Invalid touch type = %d ! No Report...\n",
 			__func__, touchType);
 		goto no_report;
@@ -3131,7 +3138,8 @@ static bool fts_enter_pointer_event_handler(struct fts_ts_info *info, unsigned
 #endif
 	/* pr_info("%s :  Event 0x%02x - ID[%d], (x, y) = (%3d, %3d)
 	 * Size = %d\n",
-	  *	__func__, *event, touchId, x, y, touchType); */
+	 *	__func__, *event, touchId, x, y, touchType); */
+	mutex_unlock(&info->input_report_mutex);
 
 	return true;
 no_report:
@@ -3149,6 +3157,8 @@ static bool fts_leave_pointer_event_handler(struct fts_ts_info *info, unsigned
 	unsigned int tool = MT_TOOL_FINGER;
 	u8 touchType;
 
+	mutex_lock(&info->input_report_mutex);
+
 	touchType = event[1] & 0x0F;
 	touchId = (event[1] & 0xF0) >> 4;
 
@@ -3181,6 +3191,7 @@ static bool fts_leave_pointer_event_handler(struct fts_ts_info *info, unsigned
 		break;
 
 	default:
+		mutex_unlock(&info->input_report_mutex);
 		pr_err("%s : Invalid touch type = %d ! No Report...\n",
 			__func__, touchType);
 		return false;
@@ -3200,6 +3211,8 @@ static bool fts_leave_pointer_event_handler(struct fts_ts_info *info, unsigned
 	}
 #endif
 
+	mutex_unlock(&info->input_report_mutex);
+
 	return true;
 }
 
@@ -4381,11 +4394,12 @@ static irqreturn_t fts_interrupt_handler(int irq, void *handle)
 #if IS_ENABLED(CONFIG_TOUCHSCREEN_OFFLOAD)
 	if (!info->offload.offload_running) {
 #endif
-
+	mutex_lock(&info->input_report_mutex);
 	if (info->touch_id == 0)
 		input_report_key(info->input_dev, BTN_TOUCH, 0);
 
 	input_sync(info->input_dev);
+	mutex_unlock(&info->input_report_mutex);
 
 #if IS_ENABLED(CONFIG_TOUCHSCREEN_OFFLOAD)
 	}
@@ -4437,6 +4451,8 @@ static void fts_offload_report(void *handle,
 	bool touch_down = 0;
 	int i;
 
+	mutex_lock(&info->input_report_mutex);
+
 	input_set_timestamp(info->input_dev, report->timestamp);
 
 	for (i = 0; i < MAX_COORDS; i++) {
@@ -4473,6 +4489,8 @@ static void fts_offload_report(void *handle,
 	input_report_key(info->input_dev, BTN_TOUCH, touch_down);
 
 	input_sync(info->input_dev);
+
+	mutex_unlock(&info->input_report_mutex);
 }
 #endif /* CONFIG_TOUCHSCREEN_OFFLOAD */
 
@@ -6319,7 +6337,7 @@ static int fts_probe(struct spi_device *client)
 
 	mutex_init(&info->diag_cmd_lock);
 
-	mutex_init(&(info->input_report_mutex));
+	mutex_init(&info->input_report_mutex);
 	mutex_init(&info->bus_mutex);
 
 	/* Assume screen is on throughout probe */
diff --git a/fts.h b/fts.h
index c2f0575..cdbe253 100644
--- a/fts.h
+++ b/fts.h
@@ -473,7 +473,7 @@ struct fts_ts_info {
 	struct wakeup_source *wakesrc;	/* Wake Lock struct */
 
 	/* input lock */
-	struct mutex input_report_mutex;	/* Mutex for pressure report */
+	struct mutex input_report_mutex;	/* Mutex for input report */
 
 	/* switches for features */
 	int gesture_enabled;	/* Gesture during suspend */