* [PATCH 1/2] nand_base: SOFT_BCH: Request strength over bytes
[not found] <2021171878.109755.1421108768347.JavaMail.zimbra@xes-inc.com>
@ 2015-01-13 0:35 ` Aaron Sierra
2015-01-14 9:34 ` Boris Brezillon
0 siblings, 1 reply; 6+ messages in thread
From: Aaron Sierra @ 2015-01-13 0:35 UTC (permalink / raw)
To: Brian Norris, David Woodhouse, Boris Brezillon, Ezequiel Garcia; +Cc: linux-mtd
Previously, we requested that drivers pass ecc.size and ecc.bytes when
using NAND_ECC_SOFT_BCH. However, a driver is likely to only know the ECC
strength required for its NAND, so each driver would need to perform a
strength-to-bytes calculation.
Avoid duplicating this calculation in each driver by asking drivers to
pass ecc.size and ecc.strength so that the strength-to-bytes calculation
need only be implemented once.
This reverts/generalizes this commit:
mtd: nand: Base BCH ECC bytes on required strength
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
---
drivers/mtd/nand/nand_base.c | 21 +++++++++++++++------
drivers/mtd/nand/sunxi_nand.c | 2 --
2 files changed, 15 insertions(+), 8 deletions(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 41585df..993612c 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -4028,22 +4028,31 @@ int nand_scan_tail(struct mtd_info *mtd)
ecc->read_oob = nand_read_oob_std;
ecc->write_oob = nand_write_oob_std;
/*
- * Board driver should supply ecc.size and ecc.bytes values to
- * select how many bits are correctable; see nand_bch_init()
- * for details. Otherwise, default to 4 bits for large page
- * devices.
+ * Board driver should supply ecc.size and ecc.strength values
+ * to select how many bits are correctable. Otherwise, default
+ * to 4 bits for large page devices.
*/
if (!ecc->size && (mtd->oobsize >= 64)) {
ecc->size = 512;
- ecc->bytes = DIV_ROUND_UP(13 * ecc->strength, 8);
+ ecc->strength = 4;
}
+
+ /*
+ * We previously recommended drivers pass ecc.size and
+ * ecc.bytes. Continue to support drivers that do.
+ * See nand_bch_init() for details.
+ */
+ if (ecc->bytes && !ecc->strength)
+ ecc->strength = ecc->bytes * 8 / fls(8 * ecc->size);
+
+ ecc->bytes = DIV_ROUND_UP(
+ ecc->strength * fls(8 * ecc->size), 8);
ecc->priv = nand_bch_init(mtd, ecc->size, ecc->bytes,
&ecc->layout);
if (!ecc->priv) {
pr_warn("BCH ECC initialization failed!\n");
BUG();
}
- ecc->strength = ecc->bytes * 8 / fls(8 * ecc->size);
break;
case NAND_ECC_NONE:
diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index ccaa8e2..6f93b29 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -1110,8 +1110,6 @@ static int sunxi_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
switch (ecc->mode) {
case NAND_ECC_SOFT_BCH:
- ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * ecc->size),
- 8);
break;
case NAND_ECC_HW:
ret = sunxi_nand_hw_ecc_ctrl_init(mtd, ecc, np);
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] nand_base: SOFT_BCH: Request strength over bytes
2015-01-13 0:35 ` [PATCH 1/2] nand_base: SOFT_BCH: Request strength over bytes Aaron Sierra
@ 2015-01-14 9:34 ` Boris Brezillon
2015-01-14 19:08 ` Aaron Sierra
2015-01-14 23:41 ` [PATCH 1/2 v2] " Aaron Sierra
0 siblings, 2 replies; 6+ messages in thread
From: Boris Brezillon @ 2015-01-14 9:34 UTC (permalink / raw)
To: Aaron Sierra; +Cc: linux-mtd, Brian Norris, David Woodhouse, Ezequiel Garcia
Hi Aaron,
On Mon, 12 Jan 2015 18:35:55 -0600 (CST)
Aaron Sierra <asierra@xes-inc.com> wrote:
> Previously, we requested that drivers pass ecc.size and ecc.bytes when
> using NAND_ECC_SOFT_BCH. However, a driver is likely to only know the ECC
> strength required for its NAND, so each driver would need to perform a
> strength-to-bytes calculation.
>
> Avoid duplicating this calculation in each driver by asking drivers to
> pass ecc.size and ecc.strength so that the strength-to-bytes calculation
> need only be implemented once.
>
> This reverts/generalizes this commit:
> mtd: nand: Base BCH ECC bytes on required strength
Apart from the nit below, you can add my:
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
>
> Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
> ---
> drivers/mtd/nand/nand_base.c | 21 +++++++++++++++------
> drivers/mtd/nand/sunxi_nand.c | 2 --
> 2 files changed, 15 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> index 41585df..993612c 100644
> --- a/drivers/mtd/nand/nand_base.c
> +++ b/drivers/mtd/nand/nand_base.c
> @@ -4028,22 +4028,31 @@ int nand_scan_tail(struct mtd_info *mtd)
> ecc->read_oob = nand_read_oob_std;
> ecc->write_oob = nand_write_oob_std;
> /*
> - * Board driver should supply ecc.size and ecc.bytes values to
> - * select how many bits are correctable; see nand_bch_init()
> - * for details. Otherwise, default to 4 bits for large page
> - * devices.
> + * Board driver should supply ecc.size and ecc.strength values
> + * to select how many bits are correctable. Otherwise, default
> + * to 4 bits for large page devices.
> */
> if (!ecc->size && (mtd->oobsize >= 64)) {
> ecc->size = 512;
> - ecc->bytes = DIV_ROUND_UP(13 * ecc->strength, 8);
> + ecc->strength = 4;
> }
> +
> + /*
> + * We previously recommended drivers pass ecc.size and
> + * ecc.bytes. Continue to support drivers that do.
> + * See nand_bch_init() for details.
> + */
> + if (ecc->bytes && !ecc->strength)
> + ecc->strength = ecc->bytes * 8 / fls(8 * ecc->size);
How about fixing all NAND_ECC_SOFT_BCH users (AFAICT the only remaining
one is nandsim, since you fixed sunxi_nand) instead of keeping this
backward compat code.
Best Regards,
Boris
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] nand_base: SOFT_BCH: Request strength over bytes
2015-01-14 9:34 ` Boris Brezillon
@ 2015-01-14 19:08 ` Aaron Sierra
2015-01-14 23:41 ` [PATCH 1/2 v2] " Aaron Sierra
1 sibling, 0 replies; 6+ messages in thread
From: Aaron Sierra @ 2015-01-14 19:08 UTC (permalink / raw)
To: Boris Brezillon; +Cc: linux-mtd, Brian Norris, David Woodhouse, Ezequiel Garcia
----- Original Message -----
> From: "Boris Brezillon" <boris.brezillon@free-electrons.com>
> Sent: Wednesday, January 14, 2015 3:34:49 AM
>
> Hi Aaron,
>
> On Mon, 12 Jan 2015 18:35:55 -0600 (CST)
> Aaron Sierra <asierra@xes-inc.com> wrote:
>
> > Previously, we requested that drivers pass ecc.size and ecc.bytes when
> > using NAND_ECC_SOFT_BCH. However, a driver is likely to only know the ECC
> > strength required for its NAND, so each driver would need to perform a
> > strength-to-bytes calculation.
> >
> > Avoid duplicating this calculation in each driver by asking drivers to
> > pass ecc.size and ecc.strength so that the strength-to-bytes calculation
> > need only be implemented once.
> >
> > This reverts/generalizes this commit:
> > mtd: nand: Base BCH ECC bytes on required strength
>
> Apart from the nit below, you can add my:
>
> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
>
> >
> > Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
> > ---
> > drivers/mtd/nand/nand_base.c | 21 +++++++++++++++------
> > drivers/mtd/nand/sunxi_nand.c | 2 --
> > 2 files changed, 15 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> > index 41585df..993612c 100644
> > --- a/drivers/mtd/nand/nand_base.c
> > +++ b/drivers/mtd/nand/nand_base.c
> > @@ -4028,22 +4028,31 @@ int nand_scan_tail(struct mtd_info *mtd)
> > ecc->read_oob = nand_read_oob_std;
> > ecc->write_oob = nand_write_oob_std;
> > /*
> > - * Board driver should supply ecc.size and ecc.bytes values to
> > - * select how many bits are correctable; see nand_bch_init()
> > - * for details. Otherwise, default to 4 bits for large page
> > - * devices.
> > + * Board driver should supply ecc.size and ecc.strength values
> > + * to select how many bits are correctable. Otherwise, default
> > + * to 4 bits for large page devices.
> > */
> > if (!ecc->size && (mtd->oobsize >= 64)) {
> > ecc->size = 512;
> > - ecc->bytes = DIV_ROUND_UP(13 * ecc->strength, 8);
> > + ecc->strength = 4;
> > }
> > +
> > + /*
> > + * We previously recommended drivers pass ecc.size and
> > + * ecc.bytes. Continue to support drivers that do.
> > + * See nand_bch_init() for details.
> > + */
> > + if (ecc->bytes && !ecc->strength)
> > + ecc->strength = ecc->bytes * 8 / fls(8 * ecc->size);
>
> How about fixing all NAND_ECC_SOFT_BCH users (AFAICT the only remaining
> one is nandsim, since you fixed sunxi_nand) instead of keeping this
> backward compat code.
Boris,
Yes, nandsim was the only other that I found. I will submit an update that
does not include this backward compatibility code, thanks.
-Aaron
>
> Best Regards,
>
> Boris
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/2 v2] nand_base: SOFT_BCH: Request strength over bytes
2015-01-14 9:34 ` Boris Brezillon
2015-01-14 19:08 ` Aaron Sierra
@ 2015-01-14 23:41 ` Aaron Sierra
2015-01-29 16:46 ` Aaron Sierra
1 sibling, 1 reply; 6+ messages in thread
From: Aaron Sierra @ 2015-01-14 23:41 UTC (permalink / raw)
To: Brian Norris, David Woodhouse, Ezequiel Garcia, Boris Brezillon; +Cc: linux-mtd
Previously, we requested that drivers pass ecc.size and ecc.bytes when
using NAND_ECC_SOFT_BCH. However, a driver is likely to only know the ECC
strength required for its NAND, so each driver would need to perform a
strength-to-bytes calculation.
Avoid duplicating this calculation in each driver by asking drivers to
pass ecc.size and ecc.strength so that the strength-to-bytes calculation
need only be implemented once.
This reverts/generalizes this commit:
mtd: nand: Base BCH ECC bytes on required strength
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
v2:
* nandsim: Set ECC strength to chip->ecc.strength
* nand_base: Don't provide ECC bytes-to-strength backward compat
drivers/mtd/nand/nand_base.c | 14 ++++++++------
drivers/mtd/nand/nandsim.c | 1 +
drivers/mtd/nand/sunxi_nand.c | 2 --
3 files changed, 9 insertions(+), 8 deletions(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 41585df..2f9c0bf 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -4028,22 +4028,24 @@ int nand_scan_tail(struct mtd_info *mtd)
ecc->read_oob = nand_read_oob_std;
ecc->write_oob = nand_write_oob_std;
/*
- * Board driver should supply ecc.size and ecc.bytes values to
- * select how many bits are correctable; see nand_bch_init()
- * for details. Otherwise, default to 4 bits for large page
- * devices.
+ * Board driver should supply ecc.size and ecc.strength values
+ * to select how many bits are correctable. Otherwise, default
+ * to 4 bits for large page devices.
*/
if (!ecc->size && (mtd->oobsize >= 64)) {
ecc->size = 512;
- ecc->bytes = DIV_ROUND_UP(13 * ecc->strength, 8);
+ ecc->strength = 4;
}
+
+ /* See nand_bch_init() for details. */
+ ecc->bytes = DIV_ROUND_UP(
+ ecc->strength * fls(8 * ecc->size), 8);
ecc->priv = nand_bch_init(mtd, ecc->size, ecc->bytes,
&ecc->layout);
if (!ecc->priv) {
pr_warn("BCH ECC initialization failed!\n");
BUG();
}
- ecc->strength = ecc->bytes * 8 / fls(8 * ecc->size);
break;
case NAND_ECC_NONE:
diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index ab5bbf5..0ed1464 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -2343,6 +2343,7 @@ static int __init ns_init_module(void)
}
chip->ecc.mode = NAND_ECC_SOFT_BCH;
chip->ecc.size = 512;
+ chip->ecc.strength = bch;
chip->ecc.bytes = eccbytes;
NS_INFO("using %u-bit/%u bytes BCH ECC\n", bch, chip->ecc.size);
}
diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index ccaa8e2..6f93b29 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -1110,8 +1110,6 @@ static int sunxi_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
switch (ecc->mode) {
case NAND_ECC_SOFT_BCH:
- ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * ecc->size),
- 8);
break;
case NAND_ECC_HW:
ret = sunxi_nand_hw_ecc_ctrl_init(mtd, ecc, np);
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2 v2] nand_base: SOFT_BCH: Request strength over bytes
2015-01-14 23:41 ` [PATCH 1/2 v2] " Aaron Sierra
@ 2015-01-29 16:46 ` Aaron Sierra
2015-02-02 5:12 ` Brian Norris
0 siblings, 1 reply; 6+ messages in thread
From: Aaron Sierra @ 2015-01-29 16:46 UTC (permalink / raw)
To: Brian Norris, David Woodhouse, Ezequiel Garcia, Boris Brezillon; +Cc: linux-mtd
----- Original Message -----
> From: "Aaron Sierra" <asierra@xes-inc.com>
> Sent: Wednesday, January 14, 2015 5:41:31 PM
>
> Previously, we requested that drivers pass ecc.size and ecc.bytes when
> using NAND_ECC_SOFT_BCH. However, a driver is likely to only know the ECC
> strength required for its NAND, so each driver would need to perform a
> strength-to-bytes calculation.
>
> Avoid duplicating this calculation in each driver by asking drivers to
> pass ecc.size and ecc.strength so that the strength-to-bytes calculation
> need only be implemented once.
>
> This reverts/generalizes this commit:
> mtd: nand: Base BCH ECC bytes on required strength
>
> Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
> v2:
> * nandsim: Set ECC strength to chip->ecc.strength
> * nand_base: Don't provide ECC bytes-to-strength backward compat
>
> drivers/mtd/nand/nand_base.c | 14 ++++++++------
> drivers/mtd/nand/nandsim.c | 1 +
> drivers/mtd/nand/sunxi_nand.c | 2 --
> 3 files changed, 9 insertions(+), 8 deletions(-)
>
Is this patch still being considered despite the changes requested for
the 2nd patch in this series?
-Aaron
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2 v2] nand_base: SOFT_BCH: Request strength over bytes
2015-01-29 16:46 ` Aaron Sierra
@ 2015-02-02 5:12 ` Brian Norris
0 siblings, 0 replies; 6+ messages in thread
From: Brian Norris @ 2015-02-02 5:12 UTC (permalink / raw)
To: Aaron Sierra; +Cc: Boris Brezillon, David Woodhouse, Ezequiel Garcia, linux-mtd
On Thu, Jan 29, 2015 at 10:46:08AM -0600, Aaron Sierra wrote:
> ----- Original Message -----
> > From: "Aaron Sierra" <asierra@xes-inc.com>
> > Sent: Wednesday, January 14, 2015 5:41:31 PM
> >
> > Previously, we requested that drivers pass ecc.size and ecc.bytes when
> > using NAND_ECC_SOFT_BCH. However, a driver is likely to only know the ECC
> > strength required for its NAND, so each driver would need to perform a
> > strength-to-bytes calculation.
> >
> > Avoid duplicating this calculation in each driver by asking drivers to
> > pass ecc.size and ecc.strength so that the strength-to-bytes calculation
> > need only be implemented once.
> >
> > This reverts/generalizes this commit:
> > mtd: nand: Base BCH ECC bytes on required strength
> >
> > Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
> > Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> > ---
> > v2:
> > * nandsim: Set ECC strength to chip->ecc.strength
> > * nand_base: Don't provide ECC bytes-to-strength backward compat
> >
> > drivers/mtd/nand/nand_base.c | 14 ++++++++------
> > drivers/mtd/nand/nandsim.c | 1 +
> > drivers/mtd/nand/sunxi_nand.c | 2 --
> > 3 files changed, 9 insertions(+), 8 deletions(-)
> >
>
> Is this patch still being considered despite the changes requested for
> the 2nd patch in this series?
Sorry, I thought I had queued it up. Pushed this patch to l2-mtd.git
now. Thanks.
Brian
^ permalink raw reply [flat|nested] 6+ messages in thread
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2015-01-13 0:35 ` [PATCH 1/2] nand_base: SOFT_BCH: Request strength over bytes Aaron Sierra
2015-01-14 9:34 ` Boris Brezillon
2015-01-14 19:08 ` Aaron Sierra
2015-01-14 23:41 ` [PATCH 1/2 v2] " Aaron Sierra
2015-01-29 16:46 ` Aaron Sierra
2015-02-02 5:12 ` Brian Norris
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