diff options
| -rw-r--r-- | drivers/mtd/nand/raw/nand_base.c | 34 |
1 files changed, 20 insertions, 14 deletions
diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index 3b3ce2926f5d..bcfd99a1699f 100644 --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -3466,30 +3466,36 @@ static void rawnand_enable_cont_reads(struct nand_chip *chip, unsigned int page, u32 readlen, int col) { struct mtd_info *mtd = nand_to_mtd(chip); - unsigned int end_page, end_col; + unsigned int first_page, last_page; chip->cont_read.ongoing = false; if (!chip->controller->supported_op.cont_read) return; - end_page = DIV_ROUND_UP(col + readlen, mtd->writesize); - end_col = (col + readlen) % mtd->writesize; + /* + * Don't bother making any calculations if the length is too small. + * Side effect: avoids possible integer underflows below. + */ + if (readlen < (2 * mtd->writesize)) + return; + /* Derive the page where continuous read should start (the first full page read) */ + first_page = page; if (col) - page++; - - if (end_col && end_page) - end_page--; + first_page++; - if (page + 1 > end_page) - return; - - chip->cont_read.first_page = page; - chip->cont_read.last_page = end_page; - chip->cont_read.ongoing = true; + /* Derive the page where continuous read should stop (the last full page read) */ + last_page = page + ((col + readlen) / mtd->writesize) - 1; - rawnand_cap_cont_reads(chip); + /* Configure and enable continuous read when suitable */ + if (first_page < last_page) { + chip->cont_read.first_page = first_page; + chip->cont_read.last_page = last_page; + chip->cont_read.ongoing = true; + /* May reset the ongoing flag */ + rawnand_cap_cont_reads(chip); + } } static void rawnand_cont_read_skip_first_page(struct nand_chip *chip, unsigned int page) |