Patchwork [U-Boot] mtd: nand: fix the written length when nand_write_skip_bad failed

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Submitter htbegin
Date March 2, 2013, 9:01 a.m.
Message ID <1362214870-7464-1-git-send-email-hotforest@gmail.com>
Download mbox | patch
Permalink /patch/224476/
State Changes Requested
Delegated to: Scott Wood
Headers show

Comments

htbegin - March 2, 2013, 9:01 a.m.
When the data has been partially written into the NAND Flash,
returning the written length instead of 0. The written length
may be useful when the upper level decides to continue the writing
after skipping the block causing the write failure.

Signed-off-by: Tao Hou <hotforest@gmail.com>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Ben Gardiner <bengardiner@nanometrics.ca>
Cc: Lei Wen <leiwen@marvell.com>
---
 drivers/mtd/nand/nand_util.c |   22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)
htbegin - March 6, 2013, 2:56 p.m.
Hi, Scott

Thanks for your review.

On Tue, Mar 5, 2013 at 9:58 AM, Scott Wood <scottwood@freescale.com> wrote:
> On 03/02/2013 03:01:10 AM, Tao Hou wrote:
>>
>> When the data has been partially written into the NAND Flash,
>> returning the written length instead of 0. The written length
>> may be useful when the upper level decides to continue the writing
>> after skipping the block causing the write failure.
>
>
> We already do that in some code paths.
>
>
>> Signed-off-by: Tao Hou <hotforest@gmail.com>
>> Cc: Scott Wood <scottwood@freescale.com>
>> Cc: Ben Gardiner <bengardiner@nanometrics.ca>
>> Cc: Lei Wen <leiwen@marvell.com>
>> ---
>>  drivers/mtd/nand/nand_util.c |   22 +++++++++++++++-------
>>  1 file changed, 15 insertions(+), 7 deletions(-)
>
>
> Could you rebase this on top of this patch:
> http://patchwork.ozlabs.org/patch/224842/
Do you mean a V2 patch ?

> BTW, are you actually using WITH_YAFFS_OOB?  I think there are some other
> things wrong with it at the moment, as mentioned here:
> http://lists.denx.de/pipermail/u-boot/2013-March/148378.html
No, I don't use it.

>
>
>> diff --git a/drivers/mtd/nand/nand_util.c b/drivers/mtd/nand/nand_util.c
>> index de1d13e..f57d723 100644
>> --- a/drivers/mtd/nand/nand_util.c
>> +++ b/drivers/mtd/nand/nand_util.c
>> @@ -496,8 +496,10 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t
>> offset, size_t *length,
>>
>>  #ifdef CONFIG_CMD_NAND_YAFFS
>>         if (flags & WITH_YAFFS_OOB) {
>> -               if (flags & ~WITH_YAFFS_OOB)
>> +               if (flags & ~WITH_YAFFS_OOB) {
>> +                       *length = 0;
>>                         return -EINVAL;
>> +               }
>>
>>                 int pages;
>>                 pages = nand->erasesize / nand->writesize;
>> @@ -505,6 +507,7 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t
>> offset, size_t *length,
>>                 if (*length % (nand->writesize + nand->oobsize)) {
>>                         printf("Attempt to write incomplete page"
>>                                 " in yaffs mode\n");
>> +                       *length = 0;
>>                         return -EINVAL;
>>                 }
>>         } else
>> @@ -542,7 +545,6 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t
>> offset, size_t *length,
>>                 if (rval == 0)
>>                         return 0;
>>
>> -               *length = 0;
>>                 printf("NAND write to offset %llx failed %d\n",
>>                         offset, rval);
>>                 return rval;
>
>
> OK so far...
>
>
>> @@ -550,7 +552,7 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t
>> offset, size_t *length,
>>
>>         while (left_to_write > 0) {
>>                 size_t block_offset = offset & (nand->erasesize - 1);
>> -               size_t write_size, truncated_write_size;
>> +               size_t write_size, truncated_write_size, written_size;
>>
>>                 WATCHDOG_RESET();
>>
>> @@ -586,8 +588,10 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t
>> offset, size_t *length,
>>                                 ops.oobbuf = ops.datbuf + pagesize;
>>
>>                                 rval = nand->write_oob(nand, offset,
>> &ops);
>> -                               if (rval != 0)
>> +                               if (rval != 0) {
>> +                                       written_size = pagesize_oob *
>> page;
>>                                         break;
>> +                               }
>>
>>                                 offset += pagesize;
>>                                 p_buffer += pagesize_oob;
>> @@ -605,14 +609,18 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t
>> offset, size_t *length,
>>
>>                         rval = nand_write(nand, offset,
>> &truncated_write_size,
>>                                         p_buffer);
>> -                       offset += write_size;
>> -                       p_buffer += write_size;
>> +                       if (rval == 0) {
>> +                               offset += write_size;
>> +                               p_buffer += write_size;
>> +                       } else {
>> +                               written_size = truncated_write_size;
>> +                       }
>>                 }
>>
>>                 if (rval != 0) {
>>                         printf("NAND write to offset %llx failed %d\n",
>>                                 offset, rval);
>> -                       *length -= left_to_write;
>> +                       *length -= left_to_write - written_size;
>>                         return rval;
>>                 }
>
>
> ...but I don't see why this part is needed (or correct).  Why doesn't
> "*length -= left_to_write" already get you what you want?
>
> -Scott
I just use "*length -= left_to_write - written_size" to tell the upper
level that what
had been actually happened. For the current block, "written_size" has
been written to the NAND Flash yet, so left_to_write should be
subtracted by "written_size".

Cheers,
Hou.
Scott Wood - March 6, 2013, 6:22 p.m.
On 03/06/2013 08:56:56 AM, htbegin wrote:
> Hi, Scott
> 
> Thanks for your review.
> 
> On Tue, Mar 5, 2013 at 9:58 AM, Scott Wood <scottwood@freescale.com>  
> wrote:
> > On 03/02/2013 03:01:10 AM, Tao Hou wrote:
> >>
> >> When the data has been partially written into the NAND Flash,
> >> returning the written length instead of 0. The written length
> >> may be useful when the upper level decides to continue the writing
> >> after skipping the block causing the write failure.
> >
> >
> > We already do that in some code paths.
> >
> >
> >> Signed-off-by: Tao Hou <hotforest@gmail.com>
> >> Cc: Scott Wood <scottwood@freescale.com>
> >> Cc: Ben Gardiner <bengardiner@nanometrics.ca>
> >> Cc: Lei Wen <leiwen@marvell.com>
> >> ---
> >>  drivers/mtd/nand/nand_util.c |   22 +++++++++++++++-------
> >>  1 file changed, 15 insertions(+), 7 deletions(-)
> >
> >
> > Could you rebase this on top of this patch:
> > http://patchwork.ozlabs.org/patch/224842/
> Do you mean a V2 patch ?

Yes.

> > BTW, are you actually using WITH_YAFFS_OOB?  I think there are some  
> other
> > things wrong with it at the moment, as mentioned here:
> > http://lists.denx.de/pipermail/u-boot/2013-March/148378.html
> No, I don't use it.

Changes to that code should be tested by someone...

> >>                 if (rval != 0) {
> >>                         printf("NAND write to offset %llx failed  
> %d\n",
> >>                                 offset, rval);
> >> -                       *length -= left_to_write;
> >> +                       *length -= left_to_write - written_size;
> >>                         return rval;
> >>                 }
> >
> >
> > ...but I don't see why this part is needed (or correct).  Why  
> doesn't
> > "*length -= left_to_write" already get you what you want?
> >
> > -Scott
> I just use "*length -= left_to_write - written_size" to tell the upper
> level that what
> had been actually happened. For the current block, "written_size" has
> been written to the NAND Flash yet, so left_to_write should be
> subtracted by "written_size".

But left_to_write isn't decreased until after this error return, so  
that's already the case.  Subtracting written_size from left_to_write  
has the effect of increasing length by written_size, so the return  
value will now look like the error page has been written.

-Scott
htbegin - March 7, 2013, 3:02 p.m.
Hi, Scott

On Thu, Mar 7, 2013 at 2:22 AM, Scott Wood <scottwood@freescale.com> wrote:
> On 03/06/2013 08:56:56 AM, htbegin wrote:
>>
>> Hi, Scott
>>
>> Thanks for your review.
>>
>> On Tue, Mar 5, 2013 at 9:58 AM, Scott Wood <scottwood@freescale.com>
>> wrote:
>> > On 03/02/2013 03:01:10 AM, Tao Hou wrote:
>> >>
>> >> When the data has been partially written into the NAND Flash,
>> >> returning the written length instead of 0. The written length
>> >> may be useful when the upper level decides to continue the writing
>> >> after skipping the block causing the write failure.
>> >
>> >
>> > We already do that in some code paths.
>> >
>> >
>> >> Signed-off-by: Tao Hou <hotforest@gmail.com>
>> >> Cc: Scott Wood <scottwood@freescale.com>
>> >> Cc: Ben Gardiner <bengardiner@nanometrics.ca>
>> >> Cc: Lei Wen <leiwen@marvell.com>
>> >> ---
>> >>  drivers/mtd/nand/nand_util.c |   22 +++++++++++++++-------
>> >>  1 file changed, 15 insertions(+), 7 deletions(-)
>> >
>> >
>> > Could you rebase this on top of this patch:
>> > http://patchwork.ozlabs.org/patch/224842/
>> Do you mean a V2 patch ?
>
>
> Yes.
I will send a V2 patch once we reach an agreement on the
"written_length" problem.

>
>
>> > BTW, are you actually using WITH_YAFFS_OOB?  I think there are some
>> > other
>> > things wrong with it at the moment, as mentioned here:
>> > http://lists.denx.de/pipermail/u-boot/2013-March/148378.html
>> No, I don't use it.
>
>
> Changes to that code should be tested by someone...
Sorry, I can't help.

>
>
>> >>                 if (rval != 0) {
>> >>                         printf("NAND write to offset %llx failed %d\n",
>> >>                                 offset, rval);
>> >> -                       *length -= left_to_write;
>> >> +                       *length -= left_to_write - written_size;
>> >>                         return rval;
>> >>                 }
>> >
>> >
>> > ...but I don't see why this part is needed (or correct).  Why doesn't
>> > "*length -= left_to_write" already get you what you want?
>> >
>> > -Scott
>> I just use "*length -= left_to_write - written_size" to tell the upper
>> level that what
>> had been actually happened. For the current block, "written_size" has
>> been written to the NAND Flash yet, so left_to_write should be
>> subtracted by "written_size".
>
>
> But left_to_write isn't decreased until after this error return, so that's
> already the case.  Subtracting written_size from left_to_write has the
> effect of increasing length by written_size, so the return value will now
> look like the error page has been written.
>
> -Scott
No, the returned value doesn't include the length of the error page.
In no-WITH_YAFFS_OOB case,  when nand_write failed,
truncated_write_size has been
updated by nand_write to the length which has been successfully
written , so it's OK to subtract written_size from left_to_write.
In WITH_YAFFS_OOB case, when nand->write_oob failed, written_size is
also the length which  has been successfully written.

Cheers,
Hou
htbegin - March 10, 2013, 1:06 a.m.
Hi, Scott

On Fri, Mar 8, 2013 at 6:27 AM, Scott Wood <scottwood@freescale.com> wrote:

>> >> I just use "*length -= left_to_write - written_size" to tell the upper
>> >> level that what
>> >> had been actually happened. For the current block, "written_size" has
>> >> been written to the NAND Flash yet, so left_to_write should be
>> >> subtracted by "written_size".
>> >
>> >
>> > But left_to_write isn't decreased until after this error return, so
>> > that's
>> > already the case.  Subtracting written_size from left_to_write has the
>> > effect of increasing length by written_size, so the return value will
>> > now
>> > look like the error page has been written.
>> >
>> > -Scott
>> No, the returned value doesn't include the length of the error page.
>> In no-WITH_YAFFS_OOB case,  when nand_write failed,
>> truncated_write_size has been
>> updated by nand_write to the length which has been successfully
>> written , so it's OK to subtract written_size from left_to_write.
>
>
> OK, but that doesn't explain why the change is needed.  You said you wanted
> to find the block with the error.  We only write one block at a time in the
> loop.  Why do you need the specific page within the block that failed?
>
> -Scott

Yes, you are right it's OK to ignore the written length of the
write-failed block, but as I said before I just wanted to tell the
upper level what had been actually written. So if you insist the
subtraction of written_len is unnecessary, it's alright with me.

Thanks.
Hou
Scott Wood - March 11, 2013, 4:43 p.m.
On 03/09/2013 07:06:54 PM, htbegin wrote:
> Hi, Scott
> 
> On Fri, Mar 8, 2013 at 6:27 AM, Scott Wood <scottwood@freescale.com>  
> wrote:
> 
> >> >> I just use "*length -= left_to_write - written_size" to tell  
> the upper
> >> >> level that what
> >> >> had been actually happened. For the current block,  
> "written_size" has
> >> >> been written to the NAND Flash yet, so left_to_write should be
> >> >> subtracted by "written_size".
> >> >
> >> >
> >> > But left_to_write isn't decreased until after this error return,  
> so
> >> > that's
> >> > already the case.  Subtracting written_size from left_to_write  
> has the
> >> > effect of increasing length by written_size, so the return value  
> will
> >> > now
> >> > look like the error page has been written.
> >> >
> >> > -Scott
> >> No, the returned value doesn't include the length of the error  
> page.
> >> In no-WITH_YAFFS_OOB case,  when nand_write failed,
> >> truncated_write_size has been
> >> updated by nand_write to the length which has been successfully
> >> written , so it's OK to subtract written_size from left_to_write.
> >
> >
> > OK, but that doesn't explain why the change is needed.  You said  
> you wanted
> > to find the block with the error.  We only write one block at a  
> time in the
> > loop.  Why do you need the specific page within the block that  
> failed?
> >
> > -Scott
> 
> Yes, you are right it's OK to ignore the written length of the
> write-failed block, but as I said before I just wanted to tell the
> upper level what had been actually written. So if you insist the
> subtraction of written_len is unnecessary, it's alright with me.

Thanks.  I do insist -- it adds complexity.

-Scott

Patch

diff --git a/drivers/mtd/nand/nand_util.c b/drivers/mtd/nand/nand_util.c
index de1d13e..f57d723 100644
--- a/drivers/mtd/nand/nand_util.c
+++ b/drivers/mtd/nand/nand_util.c
@@ -496,8 +496,10 @@  int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
 
 #ifdef CONFIG_CMD_NAND_YAFFS
 	if (flags & WITH_YAFFS_OOB) {
-		if (flags & ~WITH_YAFFS_OOB)
+		if (flags & ~WITH_YAFFS_OOB) {
+			*length = 0;
 			return -EINVAL;
+		}
 
 		int pages;
 		pages = nand->erasesize / nand->writesize;
@@ -505,6 +507,7 @@  int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
 		if (*length % (nand->writesize + nand->oobsize)) {
 			printf("Attempt to write incomplete page"
 				" in yaffs mode\n");
+			*length = 0;
 			return -EINVAL;
 		}
 	} else
@@ -542,7 +545,6 @@  int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
 		if (rval == 0)
 			return 0;
 
-		*length = 0;
 		printf("NAND write to offset %llx failed %d\n",
 			offset, rval);
 		return rval;
@@ -550,7 +552,7 @@  int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
 
 	while (left_to_write > 0) {
 		size_t block_offset = offset & (nand->erasesize - 1);
-		size_t write_size, truncated_write_size;
+		size_t write_size, truncated_write_size, written_size;
 
 		WATCHDOG_RESET();
 
@@ -586,8 +588,10 @@  int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
 				ops.oobbuf = ops.datbuf + pagesize;
 
 				rval = nand->write_oob(nand, offset, &ops);
-				if (rval != 0)
+				if (rval != 0) {
+					written_size = pagesize_oob * page;
 					break;
+				}
 
 				offset += pagesize;
 				p_buffer += pagesize_oob;
@@ -605,14 +609,18 @@  int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
 
 			rval = nand_write(nand, offset, &truncated_write_size,
 					p_buffer);
-			offset += write_size;
-			p_buffer += write_size;
+			if (rval == 0) {
+				offset += write_size;
+				p_buffer += write_size;
+			} else {
+				written_size = truncated_write_size;
+			}
 		}
 
 		if (rval != 0) {
 			printf("NAND write to offset %llx failed %d\n",
 				offset, rval);
-			*length -= left_to_write;
+			*length -= left_to_write - written_size;
 			return rval;
 		}