[v2,2/2] Input: Inactivate slots in input_inhibit_device()

diff --git a/drivers/input/input-core-private.h b/drivers/input/input-core-private.h
new file mode 100644
index 0000000000000..116834cf88689
--- /dev/null
+++ b/drivers/input/input-core-private.h
@@ -0,0 +1,16 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _INPUT_CORE_PRIVATE_H
+#define _INPUT_CORE_PRIVATE_H
+
+/*
+ * Functions and definitions that are private to input core,
+ * should not be used by input drivers or handlers.
+ */
+
+struct input_dev;
+
+void input_mt_release_slots(struct input_dev *dev);
+void input_handle_event(struct input_dev *dev,
+			unsigned int type, unsigned int code, int value);
+
+#endif /* _INPUT_CORE_PRIVATE_H */
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index 44fe6f2f063ce..14b53dac1253b 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -8,6 +8,7 @@ 
 #include <linux/input/mt.h>
 #include <linux/export.h>
 #include <linux/slab.h>
+#include "input-core-private.h"
 
 #define TRKID_SGN	((TRKID_MAX + 1) >> 1)
 
@@ -259,10 +260,13 @@  static void __input_mt_drop_unused(struct input_dev *dev, struct input_mt *mt)
 {
 	int i;
 
+	lockdep_assert_held(&dev->event_lock);
+
 	for (i = 0; i < mt->num_slots; i++) {
-		if (!input_mt_is_used(mt, &mt->slots[i])) {
-			input_mt_slot(dev, i);
-			input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
+		if (input_mt_is_active(&mt->slots[i]) &&
+		    !input_mt_is_used(mt, &mt->slots[i])) {
+			input_handle_event(dev, EV_ABS, ABS_MT_SLOT, i);
+			input_handle_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
 		}
 	}
 }
@@ -278,12 +282,43 @@  void input_mt_drop_unused(struct input_dev *dev)
 	struct input_mt *mt = dev->mt;
 
 	if (mt) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&dev->event_lock, flags);
+
 		__input_mt_drop_unused(dev, mt);
 		mt->frame++;
+
+		spin_unlock_irqrestore(&dev->event_lock, flags);
 	}
 }
 EXPORT_SYMBOL(input_mt_drop_unused);
 
+/**
+ * input_mt_release_slots() - Deactivate all slots
+ * @dev: input device with allocated MT slots
+ *
+ * Lift all active slots.
+ */
+void input_mt_release_slots(struct input_dev *dev)
+{
+	struct input_mt *mt = dev->mt;
+
+	lockdep_assert_held(&dev->event_lock);
+
+	if (mt) {
+		/* This will effectively mark all slots unused. */
+		mt->frame++;
+
+		__input_mt_drop_unused(dev, mt);
+
+		if (test_bit(ABS_PRESSURE, dev->absbit))
+			input_handle_event(dev, EV_ABS, ABS_PRESSURE, 0);
+
+		mt->frame++;
+	}
+}
+
 /**
  * input_mt_sync_frame() - synchronize mt frame
  * @dev: input device with allocated MT slots
@@ -300,8 +335,13 @@  void input_mt_sync_frame(struct input_dev *dev)
 	if (!mt)
 		return;
 
-	if (mt->flags & INPUT_MT_DROP_UNUSED)
+	if (mt->flags & INPUT_MT_DROP_UNUSED) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&dev->event_lock, flags);
 		__input_mt_drop_unused(dev, mt);
+		spin_unlock_irqrestore(&dev->event_lock, flags);
+	}
 
 	if ((mt->flags & INPUT_MT_POINTER) && !(mt->flags & INPUT_MT_SEMI_MT))
 		use_count = true;
diff --git a/drivers/input/input.c b/drivers/input/input.c
index 5e75b175b5949..ed415651f49e5 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -24,8 +24,10 @@ 
 #include <linux/mutex.h>
 #include <linux/rcupdate.h>
 #include "input-compat.h"
+#include "input-core-private.h"
 #include "input-poller.h"
 
+
 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
 MODULE_DESCRIPTION("Input core");
 MODULE_LICENSE("GPL");
@@ -142,6 +144,8 @@  static void input_pass_values(struct input_dev *dev,
 	struct input_handle *handle;
 	struct input_value *v;
 
+	lockdep_assert_held(&dev->event_lock);
+
 	if (!count)
 		return;
 
@@ -384,8 +388,8 @@  static void input_event_dispose(struct input_dev *dev, int disposition,
 	}
 }
 
-static void input_handle_event(struct input_dev *dev,
-			       unsigned int type, unsigned int code, int value)
+void input_handle_event(struct input_dev *dev,
+			unsigned int type, unsigned int code, int value)
 {
 	int disposition;
 
@@ -722,20 +726,21 @@  EXPORT_SYMBOL(input_close_device);
  * Simulate keyup events for all keys that are marked as pressed.
  * The function must be called with dev->event_lock held.
  */
-static void input_dev_release_keys(struct input_dev *dev)
+static bool input_dev_release_keys(struct input_dev *dev)
 {
 	bool need_sync = false;
 	int code;
 
+	lockdep_assert_held(&dev->event_lock);
+
 	if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
 		for_each_set_bit(code, dev->key, KEY_CNT) {
 			input_handle_event(dev, EV_KEY, code, 0);
 			need_sync = true;
 		}
-
-		if (need_sync)
-			input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
 	}
+
+	return need_sync;
 }
 
 /*
@@ -762,7 +767,8 @@  static void input_disconnect_device(struct input_dev *dev)
 	 * generate events even after we done here but they will not
 	 * reach any handlers.
 	 */
-	input_dev_release_keys(dev);
+	if (input_dev_release_keys(dev))
+		input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
 
 	list_for_each_entry(handle, &dev->h_list, d_node)
 		handle->open = 0;
@@ -1757,7 +1763,8 @@  void input_reset_device(struct input_dev *dev)
 	spin_lock_irqsave(&dev->event_lock, flags);
 
 	input_dev_toggle(dev, true);
-	input_dev_release_keys(dev);
+	if (input_dev_release_keys(dev))
+		input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
 
 	spin_unlock_irqrestore(&dev->event_lock, flags);
 	mutex_unlock(&dev->mutex);
@@ -1779,7 +1786,9 @@  static int input_inhibit_device(struct input_dev *dev)
 	}
 
 	spin_lock_irq(&dev->event_lock);
+	input_mt_release_slots(dev);
 	input_dev_release_keys(dev);
+	input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
 	input_dev_toggle(dev, false);
 	spin_unlock_irq(&dev->event_lock);
 
@@ -1830,7 +1839,8 @@  static int input_dev_suspend(struct device *dev)
 	 * Keys that are pressed now are unlikely to be
 	 * still pressed when we resume.
 	 */
-	input_dev_release_keys(input_dev);
+	if (input_dev_release_keys(input_dev))
+		input_handle_event(input_dev, EV_SYN, SYN_REPORT, 1);
 
 	/* Turn off LEDs and sounds, if any are active. */
 	input_dev_toggle(input_dev, false);
@@ -1864,7 +1874,8 @@  static int input_dev_freeze(struct device *dev)
 	 * Keys that are pressed now are unlikely to be
 	 * still pressed when we resume.
 	 */
-	input_dev_release_keys(input_dev);
+	if (input_dev_release_keys(input_dev))
+		input_handle_event(input_dev, EV_SYN, SYN_REPORT, 1);
 
 	spin_unlock_irq(&input_dev->event_lock);
 
diff --git a/include/linux/input/mt.h b/include/linux/input/mt.h
index 3b8580bd33c14..af7e64a76e12c 100644
--- a/include/linux/input/mt.h
+++ b/include/linux/input/mt.h
@@ -108,6 +108,7 @@  static inline void input_mt_report_slot_inactive(struct input_dev *dev)
 void input_mt_report_finger_count(struct input_dev *dev, int count);
 void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count);
 void input_mt_drop_unused(struct input_dev *dev);
+void input_mt_release_slots(struct input_dev *dev);
 
 void input_mt_sync_frame(struct input_dev *dev);