From 305b93f180b221789a6213bf3d298c6735102da1 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Tue, 23 Aug 2011 17:17:32 -0700 Subject: mtd: do not assume oobsize is power of 2 Previous generations of MTDs all used OOB sizes that were powers of 2, (e.g., 64, 128). However, newer generations of flash, especially NAND, use irregular OOB sizes that are not powers of 2 (e.g., 218, 224, 448). This means we cannot use masks like "mtd->oobsize - 1" to assume that we will get a proper bitmask for OOB operations. These masks are really only intended to hide the "page" portion of the offset, leaving any OOB offset intact, so a masking with the writesize (which *is* always a power of 2) is valid and makes more sense. This has been tested for read/write of NAND devices (nanddump/nandwrite) using nandsim and actual NAND flash. Signed-off-by: Brian Norris Signed-off-by: Artem Bityutskiy --- drivers/mtd/mtdchar.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/mtd/mtdchar.c') diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index a75d55577e49..b20625475132 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -410,7 +410,7 @@ static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd, return ret; ops.ooblen = length; - ops.ooboffs = start & (mtd->oobsize - 1); + ops.ooboffs = start & (mtd->writesize - 1); ops.datbuf = NULL; ops.mode = MTD_OOB_PLACE; @@ -421,7 +421,7 @@ static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd, if (IS_ERR(ops.oobbuf)) return PTR_ERR(ops.oobbuf); - start &= ~((uint64_t)mtd->oobsize - 1); + start &= ~((uint64_t)mtd->writesize - 1); ret = mtd->write_oob(mtd, start, &ops); if (ops.oobretlen > 0xFFFFFFFFU) @@ -452,7 +452,7 @@ static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start, return ret; ops.ooblen = length; - ops.ooboffs = start & (mtd->oobsize - 1); + ops.ooboffs = start & (mtd->writesize - 1); ops.datbuf = NULL; ops.mode = MTD_OOB_PLACE; @@ -463,7 +463,7 @@ static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start, if (!ops.oobbuf) return -ENOMEM; - start &= ~((uint64_t)mtd->oobsize - 1); + start &= ~((uint64_t)mtd->writesize - 1); ret = mtd->read_oob(mtd, start, &ops); if (put_user(ops.oobretlen, retp)) -- cgit v1.2.1