From f7190b6101e6e84ef88a107fae546abd0cdfff6f Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Fri, 15 Dec 2023 13:32:08 +0100 Subject: [PATCH] mtd: rawnand: Clarify conditions to enable continuous reads MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit 828f6df1bcba7f64729166efc7086ea657070445 upstream. The current logic is probably fine but is a bit convoluted. Plus, we don't want partial pages to be part of the sequential operation just in case the core would optimize the page read with a subpage read (which would break the sequence). This may happen on the first and last page only, so if the start offset or the end offset is not aligned with a page boundary, better avoid them to prevent any risk. Cc: stable@vger.kernel.org Fixes: 003fe4b9545b ("mtd: rawnand: Support for sequential cache reads") Signed-off-by: Miquel Raynal Tested-by: Martin Hundebøll Link: https://lore.kernel.org/linux-mtd/20231215123208.516590-5-miquel.raynal@bootlin.com Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/nand/raw/nand_base.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index 7610619..76167b8 100644 --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -3461,21 +3461,29 @@ 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; + + chip->cont_read.ongoing = false; if (!chip->controller->supported_op.cont_read) return; - if ((col && col + readlen < (3 * mtd->writesize)) || - (!col && readlen < (2 * mtd->writesize))) { - chip->cont_read.ongoing = false; + end_page = DIV_ROUND_UP(col + readlen, mtd->writesize); + end_col = (col + readlen) % mtd->writesize; + + if (col) + page++; + + if (end_col && end_page) + end_page--; + + if (page + 1 > end_page) return; - } - chip->cont_read.ongoing = true; chip->cont_read.first_page = page; - if (col) - chip->cont_read.first_page++; - chip->cont_read.last_page = page + ((readlen >> chip->page_shift) & chip->pagemask); + chip->cont_read.last_page = end_page; + chip->cont_read.ongoing = true; + rawnand_cap_cont_reads(chip); } -- 2.7.4