diff mbox

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

Message ID 20160123025713.GA90611@google.com (mailing list archive)
State New, archived
Headers show

Commit Message

Brian Norris Jan. 23, 2016, 2:57 a.m. UTC
All three look good, so pushed to l2-mtd.git/next. One comment below:

On Wed, Dec 02, 2015 at 12:01:07PM +0100, Boris Brezillon wrote:

...

> +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;

Richard suggested you use the mtd.h helper here. Patch below.

> +
> +	if (mod > ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds))
> +		mod = ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds);
> +
> +	if (ecc) {
> +		if (mtd->ecc_step_size == 512)
> +			seeds = sunxi_nfc_randomizer_ecc512_seeds;
> +		else
> +			seeds = sunxi_nfc_randomizer_ecc1024_seeds;
> +	}
> +
> +	return seeds[page % mod];
> +}

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

Comments

Boris BREZILLON Jan. 23, 2016, 8:18 a.m. UTC | #1
Hi Brian,

On Fri, 22 Jan 2016 18:57:13 -0800
Brian Norris <computersforpeace@gmail.com> wrote:

> All three look good, so pushed to l2-mtd.git/next. One comment below:

Thanks.

> 
> On Wed, Dec 02, 2015 at 12:01:07PM +0100, Boris Brezillon wrote:
> 
> ...
> 
> > +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;
> 
> Richard suggested you use the mtd.h helper here. Patch below.

Yep, I forgot to do this change.

> 
> > +
> > +	if (mod > ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds))
> > +		mod = ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds);
> > +
> > +	if (ecc) {
> > +		if (mtd->ecc_step_size == 512)
> > +			seeds = sunxi_nfc_randomizer_ecc512_seeds;
> > +		else
> > +			seeds = sunxi_nfc_randomizer_ecc1024_seeds;
> > +	}
> > +
> > +	return seeds[page % mod];
> > +}
> 
> 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 <boris.brezillon@free-electrons.com>

> ---
>  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.

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.

Thanks,

Boris
Brian Norris Jan. 23, 2016, 8:55 p.m. UTC | #2
On Sat, Jan 23, 2016 at 09:18:44AM +0100, Boris Brezillon wrote:
> On Fri, 22 Jan 2016 18:57:13 -0800
> Brian Norris <computersforpeace@gmail.com> wrote:
> > 
> > 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 <boris.brezillon@free-electrons.com>

Applied.

> > ---
> >  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
diff mbox

Patch

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);
 
 	if (mod > ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds))
 		mod = ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds);