diff options
| author | Kyungmin Park <kyungmin.park@samsung.com> | 2008-05-22 10:32:18 +0900 |
|---|---|---|
| committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2008-07-24 13:32:54 +0300 |
| commit | cadb40ccc16a26a738f1cbc963e35b21edd93e79 (patch) | |
| tree | acd1d5d02ecda07634f1c49432ddb39cd9f5d7fd /drivers/mtd/ubi/build.c | |
| parent | a0fd1efd488092951f310fdb777b8a540cf84dcb (diff) | |
UBI: avoid unnecessary division operations
UBI already checks that @min io size is the power of 2 at io_init.
It is save to use bit operations then.
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'drivers/mtd/ubi/build.c')
| -rw-r--r-- | drivers/mtd/ubi/build.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 961416ac061..ff4425de152 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -530,7 +530,11 @@ static int io_init(struct ubi_device *ubi) ubi->min_io_size = ubi->mtd->writesize; ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft; - /* Make sure minimal I/O unit is power of 2 */ + /* + * Make sure minimal I/O unit is power of 2. Note, there is no + * fundamental reason for this assumption. It is just an optimization + * which allows us to avoid costly division operations. + */ if (!is_power_of_2(ubi->min_io_size)) { ubi_err("min. I/O unit (%d) is not power of 2", ubi->min_io_size); @@ -581,7 +585,7 @@ static int io_init(struct ubi_device *ubi) if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE || ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE || ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE || - ubi->leb_start % ubi->min_io_size) { + ubi->leb_start & (ubi->min_io_size - 1)) { ubi_err("bad VID header (%d) or data offsets (%d)", ubi->vid_hdr_offset, ubi->leb_start); return -EINVAL; |