如果申请空间不足，申请不到合适的空间，需要回收new_rbb

components/drivers/ipc/ringblk_buf.c

@@ -215,6 +215,7 @@ rt_rbb_blk_t rt_rbb_blk_alloc(rt_rbb_t rbb, rt_size_t blk_size)
                 else
                 {
                     /* no space */
+                    rt_slist_insert(&rbb->free_list, &new_rbb->list);
                     new_rbb = RT_NULL;
                 }
             }
@@ -239,6 +240,7 @@ rt_rbb_blk_t rt_rbb_blk_alloc(rt_rbb_t rbb, rt_size_t blk_size)
                 else
                 {
                     /* no space */
+                    rt_slist_insert(&rbb->free_list, &new_rbb->list);
                     new_rbb = RT_NULL;
                 }
             }
@@ -246,16 +248,21 @@ rt_rbb_blk_t rt_rbb_blk_alloc(rt_rbb_t rbb, rt_size_t blk_size)
         else
         {
             /* the list is empty */
-            list_append(rbb, &new_rbb->list);
-            new_rbb->status = RT_RBB_BLK_INITED;
-            new_rbb->buf = rbb->buf;
-            new_rbb->size = blk_size;
+            if(blk_size <= rbb->buf_size)
+            {
+                list_append(rbb, &new_rbb->list);
+                new_rbb->status = RT_RBB_BLK_INITED;
+                new_rbb->buf = rbb->buf;
+                new_rbb->size = blk_size;
+            }
+            else
+            {
+                /* no space */
+                rt_slist_insert(&rbb->free_list, &new_rbb->list);
+                new_rbb = RT_NULL;
+            }
         }
     }
-    else
-    {
-        new_rbb = RT_NULL;
-    }
 
     rt_spin_unlock_irqrestore(&(rbb->spinlock), level);