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-rw-r--r--include/mtd/ubi-user.h34
1 files changed, 13 insertions, 21 deletions
diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h
index 3c4109777aff..8787349fbafe 100644
--- a/include/mtd/ubi-user.h
+++ b/include/mtd/ubi-user.h
@@ -196,23 +196,6 @@
#define UBI_MAX_RNVOL 32
/*
- * UBI data type hint constants.
- *
- * UBI_LONGTERM: long-term data
- * UBI_SHORTTERM: short-term data
- * UBI_UNKNOWN: data persistence is unknown
- *
- * These constants are used when data is written to UBI volumes in order to
- * help the UBI wear-leveling unit to find more appropriate physical
- * eraseblocks.
- */
-enum {
- UBI_LONGTERM = 1,
- UBI_SHORTTERM = 2,
- UBI_UNKNOWN = 3,
-};
-
-/*
* UBI volume type constants.
*
* @UBI_DYNAMIC_VOLUME: dynamic volume
@@ -375,25 +358,34 @@ struct ubi_rnvol_req {
* requests.
* @lnum: logical eraseblock number to change
* @bytes: how many bytes will be written to the logical eraseblock
- * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
+ * @dtype: pass "3" for better compatibility with old kernels
* @padding: reserved for future, not used, has to be zeroed
+ *
+ * The @dtype field used to inform UBI about what kind of data will be written
+ * to the LEB: long term (value 1), short term (value 2), unknown (value 3).
+ * UBI tried to pick a PEB with lower erase counter for short term data and a
+ * PEB with higher erase counter for long term data. But this was not really
+ * used because users usually do not know this and could easily mislead UBI. We
+ * removed this feature in May 2012. UBI currently just ignores the @dtype
+ * field. But for better compatibility with older kernels it is recommended to
+ * set @dtype to 3 (unknown).
*/
struct ubi_leb_change_req {
__s32 lnum;
__s32 bytes;
- __s8 dtype;
+ __s8 dtype; /* obsolete, do not use! */
__s8 padding[7];
} __packed;
/**
* struct ubi_map_req - a data structure used in map LEB requests.
+ * @dtype: pass "3" for better compatibility with old kernels
* @lnum: logical eraseblock number to unmap
- * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
* @padding: reserved for future, not used, has to be zeroed
*/
struct ubi_map_req {
__s32 lnum;
- __s8 dtype;
+ __s8 dtype; /* obsolete, do not use! */
__s8 padding[3];
} __packed;