Input: do not emit unneeded EV_SYN when suspending

Do not emit EV_SYN/SYN_REPORT on suspend if there were no keys that are
still pressed as we are suspending the device (and in all other cases when
input core is forcibly releasing keys via input_dev_release_keys() call).

Reviewed-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/input/input.c b/drivers/input/input.c
index 78d24990a816..5391abd28b27 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -674,13 +674,19 @@ EXPORT_SYMBOL(input_close_device);
  */
 static void input_dev_release_keys(struct input_dev *dev)
 {
+        bool need_sync = false;
         int code;
 
         if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
-                for_each_set_bit(code, dev->key, KEY_CNT)
+                for_each_set_bit(code, dev->key, KEY_CNT) {
                         input_pass_event(dev, EV_KEY, code, 0);
+                        need_sync = true;
+                }
+
+                if (need_sync)
+                        input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
+
                 memset(dev->key, 0, sizeof(dev->key));
-                input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
         }
 }