2 files changed, 12 insertions, 8 deletions
diff --git a/keyboards/crkbd/rev1/legacy/matrix.c b/keyboards/crkbd/rev1/legacy/matrix.c
index 46dead369..8eb028137 100644
--- a/keyboards/crkbd/rev1/legacy/matrix.c
+++ b/keyboards/crkbd/rev1/legacy/matrix.c
@@ -155,6 +155,7 @@ void matrix_init(void)
 
 uint8_t _matrix_scan(void)
 {
+    bool changed = false;
     // Right hand is stored after the left in the matirx so, we need to offset it
     int offset = isLeftHand ? 0 : (ROWS_PER_HAND);
 
@@ -163,6 +164,7 @@ uint8_t _matrix_scan(void)
         _delay_us(30);  // without this wait read unstable value.
         matrix_row_t cols = read_cols();
         if (matrix_debouncing[i+offset] != cols) {
+            changed = true;
             matrix_debouncing[i+offset] = cols;
             debouncing = DEBOUNCE;
         }
@@ -179,7 +181,7 @@ uint8_t _matrix_scan(void)
         }
     }
 
-    return 1;
+    return changed;
 }
 
 #ifdef USE_MATRIX_I2C
@@ -237,16 +239,17 @@ int serial_transaction(int master_changed) {
 
 uint8_t matrix_scan(void)
 {
+    bool changed = false;
     if (is_master) {
-        matrix_master_scan();
+        changed |= matrix_master_scan();
     }else{
-        matrix_slave_scan();
+        changed |= matrix_slave_scan();
         int offset = (isLeftHand) ? ROWS_PER_HAND : 0;
         memcpy(&matrix[offset],
                (void *)serial_master_buffer, SERIAL_MASTER_BUFFER_LENGTH);
         matrix_scan_quantum();
     }
-    return 1;
+    return (uint8_t) changed;
 }
 
 
@@ -297,8 +300,8 @@ uint8_t matrix_master_scan(void) {
     return ret;
 }
 
-void matrix_slave_scan(void) {
-    _matrix_scan();
+uint8_t matrix_slave_scan(void) {
+    int ret = _matrix_scan();
 
     int offset = (isLeftHand) ? 0 : ROWS_PER_HAND;
 
@@ -314,7 +317,7 @@ void matrix_slave_scan(void) {
     for (int i = 0; i < ROWS_PER_HAND; ++i) {
   #ifdef SERIAL_USE_MULTI_TRANSACTION
         if( serial_slave_buffer[i] != matrix[offset+i] )
-	    change = 1;
+        change = 1;
   #endif
         serial_slave_buffer[i] = matrix[offset+i];
     }
@@ -322,6 +325,7 @@ void matrix_slave_scan(void) {
     slave_buffer_change_count += change;
   #endif
 #endif
+    return ret;
 }
 
 bool matrix_is_modified(void)
diff --git a/keyboards/crkbd/rev1/legacy/split_util.h b/keyboards/crkbd/rev1/legacy/split_util.h
index 414763bff..b2ddc1f97 100644
--- a/keyboards/crkbd/rev1/legacy/split_util.h
+++ b/keyboards/crkbd/rev1/legacy/split_util.h
@@ -27,7 +27,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 extern volatile bool isLeftHand;
 
 // slave version of matix scan, defined in matrix.c
-void matrix_slave_scan(void);
+uint8_t matrix_slave_scan(void);
 
 void split_keyboard_setup(void);
 bool has_usb(void);