Don't process keycodes on the slave

keyboards/ergodox_infinity/ergodox_infinity.c

@@ -126,6 +126,10 @@ void matrix_scan_kb(void) {
 	matrix_scan_user();
 }
 
+bool is_keyboard_master(void) {
+    return is_serial_link_master();
+}
+
 __attribute__ ((weak))
 void ergodox_board_led_on(void){
 }

tmk_core/common/keyboard.c

@@ -119,6 +119,11 @@ void keyboard_setup(void) {
     matrix_setup();
 }
 
+__attribute__((weak))
+bool is_keyboard_master(void) {
+    return true;
+}
+
 void keyboard_init(void) {
     timer_init();
     matrix_init();
@@ -168,6 +173,7 @@ void keyboard_task(void)
     matrix_row_t matrix_change = 0;
 
     matrix_scan();
+    if (is_keyboard_master()) {
         for (uint8_t r = 0; r < MATRIX_ROWS; r++) {
             matrix_row = matrix_get_row(r);
             matrix_change = matrix_row ^ matrix_prev[r];
@@ -202,6 +208,7 @@ void keyboard_task(void)
                 }
             }
         }
+    }
     // call with pseudo tick event when no real key event.
     action_exec(TICK);