add a option in jffs2_config.h(whose value may be important to reading/writing speed)

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1951 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/dfs/filesystems/jffs2/jffs2_config.h

@@ -7,11 +7,14 @@
 
 #define DEVICE_PART_MAX   1  /* the max partions on a nand deivce*/
 
+/* memory page size in kernel/asm/page.h, it is correspond with flash read/write
+ * option, so this size has a great impact on reading/writing speed */
+#define CONFIG_JFFS2_PAGE_SHIFT  12  /* (1<<12) 4096bytes*/
 
 /* jffs2 support relative dir, command "ls" will get
  * +-------------------------------+
  * |   finsh>>ls("/")              |
- * |   Directory /:              |
+ * |   Directory /:                |
  * |   .                   <DIR>   |
  * |   ..                  <DIR>   |
  * |   dir1                <DIR>   |

components/dfs/filesystems/jffs2/kernel/asm/page.h

@@ -2,7 +2,8 @@
 #define __ASM_PAGE_H__
 
 //#include <pkgconf/linux_compat.h>  //mod by prife
-#define PAGE_SHIFT 12 // add by prife 4K
+#include "jffs2_config.h"
+#define PAGE_SHIFT  CONFIG_JFFS2_PAGE_SHIFT
 /* These aren't used by much yet. If that changes, you might want
    to make them actually correct :) */
 #define PAGE_SIZE  (0x1 << PAGE_SHIFT)