no need to check buffer-modified-tick

flycheck.el

@@ -2937,7 +2937,7 @@ Slots:
     ;; the focus hooks only work on Emacs 24.4 and upwards, but since undefined
     ;; hooks are perfectly ok we don't need a version guard here.  They'll just
     ;; not work silently.
-    (post-command-hook . flycheck-maybe-display-error-at-point-soon)
+    (post-command-hook . flycheck-display-error-at-point-soon)
     (focus-in-hook     . flycheck-display-error-at-point-soon)
     (focus-out-hook    . flycheck-cancel-error-display-error-at-point-timer)
     (post-command-hook . flycheck-hide-error-buffer)
@@ -5520,13 +5520,6 @@ non-nil."
     (cancel-timer flycheck-display-error-at-point-timer)
     (setq flycheck-display-error-at-point-timer nil)))
 
-(defun flycheck--error-display-tick ()
-  "Return point and tick counter of current buffer."
-  (cons (point) (buffer-modified-tick)))
-
-(defvar-local flycheck--last-error-display-tick nil
-  "Value of `flycheck--error-display-tick' when errors were last displayed.")
-
 (defun flycheck-display-error-at-point ()
   "Display all the error messages at point.
 
@@ -5536,26 +5529,17 @@ If there are no errors, clears the error messages at point."
   ;; errors
   (with-demoted-errors "Flycheck error display error: %s"
     (flycheck-cancel-error-display-error-at-point-timer)
-    (setq flycheck--last-error-display-tick (flycheck--error-display-tick))
     (when flycheck-mode
       (-if-let (errors (flycheck-overlay-errors-at (point)))
           (flycheck-display-errors errors)
         (flycheck-clear-displayed-errors)))))
 
 (defun flycheck-display-error-at-point-soon ()
   "Display error messages at point, with a delay."
-  (setq flycheck--last-error-display-tick nil)
-  (flycheck-maybe-display-error-at-point-soon))
-
-(defun flycheck-maybe-display-error-at-point-soon ()
-  "Display error message at point with a delay, unless already displayed."
   (flycheck-cancel-error-display-error-at-point-timer)
-  (when (and (not (equal flycheck--last-error-display-tick
-                         (setq flycheck--last-error-display-tick
-                               (flycheck--error-display-tick)))))
-    (setq flycheck-display-error-at-point-timer
-          (run-at-time flycheck-display-errors-delay nil
-                       'flycheck-display-error-at-point))))
+  (setq flycheck-display-error-at-point-timer
+        (run-at-time flycheck-display-errors-delay nil
+                     'flycheck-display-error-at-point)))
 
 
 ;;; Functions to display errors