🚸 More frequent button polling (#27797)

Marlin/Configuration_adv.h

@@ -2268,6 +2268,8 @@
   #define ADC_BUTTON_DEBOUNCE_DELAY 16  // (count) Increase if buttons bounce or repeat too fast
 #endif
 
+//#define FAST_BUTTON_POLLING           // Poll buttons at ~1kHz on 8-bit AVR. Set to 'false' for slow polling on 32-bit.
+
 // @section safety
 
 /**

Marlin/src/inc/Conditionals-5-post.h

@@ -3557,6 +3557,10 @@
   #define HAS_ROTARY_ENCODER 1
 #endif
 
+#if defined(CPU_32_BIT) && !defined(FAST_BUTTON_POLLING)
+  #define FAST_BUTTON_POLLING
+#endif
+
 #if PIN_EXISTS(SAFE_POWER) && DISABLED(DISABLE_DRIVER_SAFE_POWER_PROTECT)
   #define HAS_DRIVER_SAFE_POWER_PROTECT 1
 #endif

Marlin/src/module/temperature.cpp

@@ -4283,10 +4283,15 @@ void Temperature::isr() {
   #endif // SLOW_PWM_HEATERS
 
   //
-  // Update lcd buttons 488 times per second
+  // Update lcd buttons at ~488Hz or ~976Hz
   //
-  static bool do_buttons;
-  if ((do_buttons ^= true)) ui.update_buttons();
+  #if ENABLED(FAST_BUTTON_POLLING)
+    constexpr bool do_buttons = true;
+  #else
+    static bool do_buttons;
+    do_buttons ^= true;
+  #endif
+  if (do_buttons) ui.update_buttons();
 
   /**
    * One sensor is sampled on every other call of the ISR.