Messages in this thread Patch in this message | | | From | Richard Genoud <> | Subject | [PATCH 2/2] UBI: add ioctl for max_beb_per1024 | Date | Thu, 16 Aug 2012 16:52:03 +0200 |
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This patch provides the possibility to adjust the "maximum expected number of bad blocks per 1024 blocks" (max_beb_per1024) for each mtd device from UBI_IOCATT ioctl.
The majority of NAND devices have their max_beb_per1024 equal to 20, but sometimes it's more. We already could adjust that via a kernel parameter, now we can also use UBI_IOCATT ioctl: struct ubi_attach_req { __s32 ubi_num; __s32 mtd_num; __s32 vid_hdr_offset; __u8 max_beb_per1024; __s8 padding[11]; };
Signed-off-by: Richard Genoud <richard.genoud@gmail.com> --- drivers/mtd/ubi/cdev.c | 9 ++++++++- include/mtd/ubi-user.h | 19 ++++++++++++++++++- 2 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c index e0027e7..d268b42 100644 --- a/drivers/mtd/ubi/cdev.c +++ b/drivers/mtd/ubi/cdev.c @@ -1006,12 +1006,19 @@ static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd, } /* + * For compatibility with older user-space tools, + * a zero value should be treated like a default value + */ + if (!req.max_beb_per1024) + req.max_beb_per1024 = MTD_UBI_DEFAULT_BEB_LIMIT; + + /* * Note, further request verification is done by * 'ubi_attach_mtd_dev()'. */ mutex_lock(&ubi_devices_mutex); err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset, - MTD_UBI_DEFAULT_BEB_LIMIT); + req.max_beb_per1024); mutex_unlock(&ubi_devices_mutex); if (err < 0) put_mtd_device(mtd); diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h index 8787349..77cd0d1 100644 --- a/include/mtd/ubi-user.h +++ b/include/mtd/ubi-user.h @@ -222,6 +222,7 @@ 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 bad eraseblocks per 1024 eraseblocks * @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 @@ -245,12 +246,28 @@ 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 bad eraseblocks 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 0-255. If 0 is given, the default value + * MTD_UBI_DEFAULT_BEB_LIMIT will be used for compatibility. */ struct ubi_attach_req { __s32 ubi_num; __s32 mtd_num; __s32 vid_hdr_offset; - __s8 padding[12]; + __u8 max_beb_per1024; + __s8 padding[11]; }; /** -- 1.7.2.5
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