@@ -220,6 +220,7 @@ enum {
* @ubi_num: UBI device number to create
* @mtd_num: MTD device number to attach
* @vid_hdr_offset: VID header offset (use defaults if %0)
+ * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
* @padding: reserved for future, not used, has to be zeroed
*
* This data structure is used to specify MTD device UBI has to attach and the
@@ -243,12 +244,25 @@ enum {
* be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes
* aligned, which is OK, as UBI is clever enough to realize this is 4th
* sub-page of the first page and add needed padding.
+ *
+ * The @max_beb_per1024 is the maximum amount of bad PEBs UBI expects on the
+ * UBI device per 1024 eraseblocks. This value is often given in an other form
+ * in the NAND datasheet (min NVB i.e. minimal number of valid blocks). The
+ * maximum expected bad eraseblocks per 1024 is then:
+ * 1024 * (1 - MinNVB / MaxNVB)
+ * Which gives 20 for most NAND devices. This limit is used in order to derive
+ * amount of eraseblock UBI reserves for handling new bad blocks. If the device
+ * has more bad eraseblocks than this limit, UBI does not reserve any physical
+ * eraseblocks for new bad eraseblocks, but attempts to use available
+ * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the
+ * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used.
*/
struct ubi_attach_req {
int32_t ubi_num;
int32_t mtd_num;
int32_t vid_hdr_offset;
- int8_t padding[12];
+ int16_t max_beb_per1024;
+ int8_t padding[10];
};
/**
Signed-off-by: Richard Genoud <richard.genoud@gmail.com> --- include/mtd/ubi-user.h | 16 +++++++++++++++- 1 files changed, 15 insertions(+), 1 deletions(-)