Input: release pressed keys when resuming device

As the kernel has no way to know whether a key was released
while the system was asleep, keys need to be reported released
as the system is resumed, lest autorepeat set in.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 29 insertions, 10 deletions

diff --git a/drivers/input/input.c b/drivers/input/input.c
index 9c79bd56b51..240ad39da57 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -528,12 +528,30 @@ void input_close_device(struct input_handle *handle)
 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)
+{
+        int code;
+
+        if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
+                for (code = 0; code <= KEY_MAX; code++) {
+                        if (is_event_supported(code, dev->keybit, KEY_MAX) &&
+                            __test_and_clear_bit(code, dev->key)) {
+                                input_pass_event(dev, EV_KEY, code, 0);
+                        }
+                }
+                input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
+        }
+}
+
+/*
  * Prepare device for unregistering
  */
 static void input_disconnect_device(struct input_dev *dev)
 {
         struct input_handle *handle;
-        int code;
 
         /*
          * Mark device as going away. Note that we take dev->mutex here
@@ -552,15 +570,7 @@ static void input_disconnect_device(struct input_dev *dev)
          * generate events even after we done here but they will not
          * reach any handlers.
          */
-        if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
-                for (code = 0; code <= KEY_MAX; code++) {
-                        if (is_event_supported(code, dev->keybit, KEY_MAX) &&
-                            __test_and_clear_bit(code, dev->key)) {
-                                input_pass_event(dev, EV_KEY, code, 0);
-                        }
-                }
-                input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
-        }
+        input_dev_release_keys(dev);
 
         list_for_each_entry(handle, &dev->h_list, d_node)
                 handle->open = 0;
@@ -1433,6 +1443,15 @@ static int input_dev_resume(struct device *dev)
 
         mutex_lock(&input_dev->mutex);
         input_dev_reset(input_dev, true);
+
+        /*
+         * Keys that have been pressed at suspend time are unlikely
+         * to be still pressed when we resume.
+         */
+        spin_lock_irq(&input_dev->event_lock);
+        input_dev_release_keys(input_dev);
+        spin_unlock_irq(&input_dev->event_lock);
+
         mutex_unlock(&input_dev->mutex);
 
         return 0;