[PATCH] MTD: make s3c2410's correct_data indicate an error for multi-bit read errors

[PATCH] MTD: make s3c2410's correct_data indicate an error for multi-bit read errors

[Matt Reimer]

From: Matt Reimer <mreimer@vpop.net>

If there were multiple bit errors in the data s3c2410_nand_correct_data()
was returning 0 (no error) instead of -1, so the upper layers (like JFFS2)
would not know the data is corrupt.

Signed-off-by: Matt Reimer <mreimer@vpop.net>
---
 drivers/mtd/nand/s3c2410.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index 077fdcc..2e6b435 100644
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -397,7 +397,7 @@ static int s3c2410_nand_correct_data(struct mtd_info *mtd, u_char *dat,
 	if ((diff0 & ~(1<<fls(diff0))) == 0)
 		return 1;
 
-	return 0;
+	return -1;
 }
 
 /* ECC functions
-- 
1.5.3.2

[PATCH] MTD: make s3c2410's correct_data indicate an error for multi-bit read errors

[Matt Reimer]

If there were multiple bit errors in the data s3c2410_nand_correct_data()
was returning 0 (no error) instead of -1, so the upper layers (like JFFS2)
would not know the data is corrupt.

Signed-off-by: Matt Reimer <mreimer@vpop.net>
---
 drivers/mtd/nand/s3c2410.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index 077fdcc..2e6b435 100644
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -397,7 +397,7 @@ static int s3c2410_nand_correct_data(struct
mtd_info *mtd, u_char *dat,
        if ((diff0 & ~(1<<fls(diff0))) == 0)
                return 1;

-       return 0;
+       return -1;
 }

 /* ECC functions
-- 
1.5.3.2

Re: [PATCH] MTD: make s3c2410's correct_data indicate an error for multi-bit read errors

[Jörn Engel]

On Thu, 18 October 2007 18:13:07 -0700, Matt Reimer wrote:
> 
> If there were multiple bit errors in the data s3c2410_nand_correct_data()
> was returning 0 (no error) instead of -1, so the upper layers (like JFFS2)
> would not know the data is corrupt.
> 
> Signed-off-by: Matt Reimer <mreimer@vpop.net>
> ---
>  drivers/mtd/nand/s3c2410.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
> index 077fdcc..2e6b435 100644
> --- a/drivers/mtd/nand/s3c2410.c
> +++ b/drivers/mtd/nand/s3c2410.c
> @@ -397,7 +397,7 @@ static int s3c2410_nand_correct_data(struct
> mtd_info *mtd, u_char *dat,
>         if ((diff0 & ~(1<<fls(diff0))) == 0)
>                 return 1;
> 
> -       return 0;
> +       return -1;
>  }

Why don't you return -EBADMSG?

Jörn

-- 
I can say that I spend most of my time fixing bugs even if I have lots
of new features to implement in mind, but I give bugs more priority.
-- Andrea Arcangeli, 2000

Re: [PATCH] MTD: make s3c2410's correct_data indicate an error for multi-bit read errors

[Artem Bityutskiy]

On Fri, 2007-10-19 at 10:24 +0200, Jörn Engel wrote:
> > @@ -397,7 +397,7 @@ static int s3c2410_nand_correct_data(struct
> > mtd_info *mtd, u_char *dat,
> >         if ((diff0 & ~(1<<fls(diff0))) == 0)
> >                 return 1;
> > 
> > -       return 0;
> > +       return -1;
> >  }

Yup, Jörn is right, you should return -EBADMSG on ECC errors and
-EUCLEAN if there was a correctable bit-flip.

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)

Re: [PATCH] MTD: make s3c2410's correct_data indicate an error for multi-bit read errors

[Matt Reimer]

On 10/19/07, Artem Bityutskiy <dedekind@infradead.org> wrote:
> On Fri, 2007-10-19 at 10:24 +0200, Jörn Engel wrote:
> > > @@ -397,7 +397,7 @@ static int s3c2410_nand_correct_data(struct
> > > mtd_info *mtd, u_char *dat,
> > >         if ((diff0 & ~(1<<fls(diff0))) == 0)
> > >                 return 1;
> > >
> > > -       return 0;
> > > +       return -1;
> > >  }
>
> Yup, Jörn is right, you should return -EBADMSG on ECC errors and
> -EUCLEAN if there was a correctable bit-flip.

See the patch I posted a couple of days ago with the subject "MTD:
treat any negative return value from correct() as an error". Once that
patch is accepted, doing what you say will work as you expect; right
now, it results in lying to upper layers about errors.

Matt

Re: [PATCH] MTD: make s3c2410's correct_data indicate an error for multi-bit read errors

[Jörn Engel]

On Fri, 19 October 2007 12:29:45 -0700, Matt Reimer wrote:
> 
> See the patch I posted a couple of days ago with the subject "MTD:
> treat any negative return value from correct() as an error". Once that
> patch is accepted, doing what you say will work as you expect; right
> now, it results in lying to upper layers about errors.

I'll comment to that patch seperately.  This one is
Acked-By: Joern Engel <joern@logfs.org>

Jörn

-- 
It does not matter how slowly you go, so long as you do not stop.
-- Confucius

[PATCH] MTD: make s3c2410's correct_data indicate an error for multi-bit read errors

[Matt Reimer]

From: Matt Reimer <mreimer@vpop.net>

If there were multiple bit errors in the data s3c2410_nand_correct_data()
was returning 0 (no error) instead of -1, so the upper layers (like JFFS2)
would not know the data is corrupt.

Signed-off-by: Matt Reimer <mreimer@vpop.net>
---
 drivers/mtd/nand/s3c2410.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index 077fdcc..1aa3a18 100644
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -397,7 +397,7 @@ static int s3c2410_nand_correct_data(struct mtd_info *mtd, u_char *dat,
 	if ((diff0 & ~(1<<fls(diff0))) == 0)
 		return 1;
 
-	return 0;
+	return -EBADMSG;
 }
 
 /* ECC functions
-- 
1.5.3.2

[PATCH] MTD: make s3c2410's correct_data indicate an error for multi-bit read errors

[Matt Reimer]

From: Matt Reimer <mreimer@vpop.net>

If there were multiple bit errors in the data s3c2410_nand_correct_data()
was returning 0 (no error) instead of -EBADMSG, so the upper layers
(like JFFS2) would not know the data is corrupt.

Signed-off-by: Matt Reimer <mreimer@vpop.net>
---
 drivers/mtd/nand/s3c2410.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index 077fdcc..1aa3a18 100644
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -397,7 +397,7 @@ static int s3c2410_nand_correct_data(struct mtd_info *mtd, u_char *dat,
 	if ((diff0 & ~(1<<fls(diff0))) == 0)
 		return 1;
 
-	return 0;
+	return -EBADMSG;
 }
 
 /* ECC functions
-- 
1.5.3.2

Re: [PATCH] MTD: make s3c2410's correct_data indicate an error for multi-bit read errors

[Matt Reimer]

On 10/20/07, Matt Reimer <mattjreimer@gmail.com> wrote:
> From: Matt Reimer <mreimer@vpop.net>
>
> If there were multiple bit errors in the data s3c2410_nand_correct_data()
> was returning 0 (no error) instead of -1, so the upper layers (like JFFS2)
> would not know the data is corrupt.

Grr, ignore this patch, as I forget to amend the commit message. The
next one should get it right.

Matt

Re: [PATCH] MTD: make s3c2410's correct_data indicate an error for multi-bit read errors

[Matt Reimer]

Anyone willing to ACK this patch?

Matt

On 10/20/07, Matt Reimer <mattjreimer@gmail.com> wrote:
> From: Matt Reimer <mreimer@vpop.net>
>
> If there were multiple bit errors in the data s3c2410_nand_correct_data()
> was returning 0 (no error) instead of -EBADMSG, so the upper layers
> (like JFFS2) would not know the data is corrupt.
>
> Signed-off-by: Matt Reimer <mreimer@vpop.net>
> ---
>  drivers/mtd/nand/s3c2410.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
> index 077fdcc..1aa3a18 100644
> --- a/drivers/mtd/nand/s3c2410.c
> +++ b/drivers/mtd/nand/s3c2410.c
> @@ -397,7 +397,7 @@ static int s3c2410_nand_correct_data(struct mtd_info *mtd, u_char *dat,
>         if ((diff0 & ~(1<<fls(diff0))) == 0)
>                 return 1;
>
> -       return 0;
> +       return -EBADMSG;
>  }
>
>  /* ECC functions
> --
> 1.5.3.2
>
>
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