[PATCH v2 3/3] mtd: nand: sunxi: add randomizer support

On Sat, Jan 23, 2016 at 09:18:44AM +0100, Boris Brezillon wrote:

On Fri, 22 Jan 2016 18:57:13 -0800
Brian Norris [off-list ref] wrote:

quoted

From: Brian Norris <computersforpeace@gmail.com>
Date: Fri, 22 Jan 2016 18:54:02 -0800
Subject: [PATCH] mtd: nand: sunxi: use mtd_div_by_ws() helper

Suggested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Acked-by: Boris Brezillon <redacted>

Applied.

quoted

---
 drivers/mtd/nand/sunxi_nand.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index 5f700719d5c2..b5ea6b312df0 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c

@@ -624,7 +624,7 @@ static u16 sunxi_nfc_randomizer_step(u16 state, int count)
 static u16 sunxi_nfc_randomizer_state(struct mtd_info *mtd, int page, bool ecc)
 {
 	const u16 *seeds = sunxi_nfc_randomizer_page_seeds;
-	int mod = mtd->erasesize / mtd->writesize;
+	int mod = mtd_div_by_ws(mtd->erasesize, mtd);

Just a comment (which should not prevent you from applying this patch).
Isn't it a bit overkill to cast the erasesize to a 64 bit value, and
then do a do_div on it. Shouldn't happen often though, because
->writesize_shift should be != 0 in most (all?) cases.

drivers/mtd/nand/ assumes power-of-2 dimensions for many things, so
probably.

Another related remark: with the MLC/paired pages stuff I'll have to
retrieve this information (number of write units per erase block) quite
often, so maybe we should have a field (and/or an helper) for that.

Perhaps.

Brian