🔧 Allow arbitrary BLOCK_BUFFER_SIZE

Marlin/Configuration_adv.h

@@ -2526,7 +2526,6 @@
 // @section motion
 
 // The number of linear moves that can be in the planner at once.
-// The value of BLOCK_BUFFER_SIZE must be a power of 2 (e.g., 8, 16, 32)
 #if ALL(HAS_MEDIA, DIRECT_STEPPING)
   #define BLOCK_BUFFER_SIZE  8
 #elif HAS_MEDIA

Marlin/src/feature/max7219.cpp

@@ -706,7 +706,7 @@ void Max7219::idle_tasks() {
 
   #ifdef MAX7219_DEBUG_PLANNER_QUEUE
     static int16_t last_depth = 0;
-    const int16_t current_depth = (head - tail + BLOCK_BUFFER_SIZE) & (BLOCK_BUFFER_SIZE - 1) & 0xF;
+    const int16_t current_depth = BLOCK_MOD(head - tail + (BLOCK_BUFFER_SIZE)) & 0xF;
     if (current_depth != last_depth) {
       quantity16(MAX7219_DEBUG_PLANNER_QUEUE, last_depth, current_depth, &row_change_mask);
       last_depth = current_depth;

Marlin/src/module/planner.h

@@ -310,7 +310,11 @@ typedef struct PlannerBlock {
   #define HAS_POSITION_FLOAT 1
 #endif
 
-#define BLOCK_MOD(n) ((n)&(BLOCK_BUFFER_SIZE-1))
+#if IS_POWER_OF_2(BLOCK_BUFFER_SIZE)
+  #define BLOCK_MOD(n) ((n)&((BLOCK_BUFFER_SIZE)-1))
+#else
+  #define BLOCK_MOD(n) ((n)%(BLOCK_BUFFER_SIZE))
+#endif
 
 #if ENABLED(LASER_FEATURE)
   typedef struct {
@@ -366,7 +370,7 @@ typedef struct {
 #endif
 
 #if ENABLED(DISABLE_OTHER_EXTRUDERS)
-  typedef uvalue_t(BLOCK_BUFFER_SIZE * 2) last_move_t;
+  typedef uvalue_t((BLOCK_BUFFER_SIZE) * 2) last_move_t;
 #endif
 
 #if ENABLED(ARC_SUPPORT)
@@ -780,7 +784,7 @@ class Planner {
     FORCE_INLINE static bool is_full() { return block_buffer_tail == next_block_index(block_buffer_head); }
 
     // Get count of movement slots free
-    FORCE_INLINE static uint8_t moves_free() { return BLOCK_BUFFER_SIZE - 1 - movesplanned(); }
+    FORCE_INLINE static uint8_t moves_free() { return (BLOCK_BUFFER_SIZE) - 1 - movesplanned(); }
 
     /**
      * Planner::get_next_free_block