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-rw-r--r--drivers/mtd/nand/raw/nand_base.c34
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)