A portion of the `check_pattern()' function is basically a `memcmp()'.
Since it's possible for `memcmp()' to be optimized for a particular
architecture, we should use it instead.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Updates to our default function for creating bad block patterns have
broken the "no OOB" feature. The NAND_BBT_NO_OOB option should not be
set while scanning for bad blocks, but we've been passing all BBT
options from nand_chip.bbt_options to the bad block scan. This causes us
to hit the:
BUG_ON(bd->options & NAND_BBT_NO_OOB);
in create_bbt() when we scan the flash for bad blocks.
Thus, while it can be legal to set NAND_BBT_NO_OOB in a custom badblock
pattern descriptor (presumably with NAND_BBT_CREATE disabled?), we
should not pass it through in our default function.
Also, to help clarify and emphasize that the function creates bad block
patterns only (not, for example, table descriptors for locating
flash-based BBT), I renamed `nand_create_default_bbt_descr' to
`nand_create_badblock_pattern'.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Because there are so many cases of checking, writing, and re-writing of
the bad block table(s), we might as well wait until the we've settled on
a valid, clean copy of the table. This also prevents us from falsely
incrementing the table version. For example, we may have the following:
Primary table, with version 0x02
Mirror table, with version 0x01
Primary table has uncorrectable ECC errors
If we don't have this fix applied, then we will:
Choose to read the primary table (higher version)
Set mirror table version to 0x02
Read back primary table
Invalidate table because of ECC errors
Retry readback operation with mirror table, now version 0x02
Mirrored table reads cleanly
Writeback BBT to primary table location (with "version 0x02")
However, the mirrored table shouldn't have a new version number.
Instead, we actually want:
Choose to read the primary table (higher version)
Read back primary table
Invalidate table because of ECC errors
Retry readback with mirror table (version 0x01)
Mirrored table reads cleanly
Set both tables to version 0x01
Writeback BBT to primary table location (version 0x01)
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Now that `read_bbt()' returns ECC error codes properly, we handle those
codes when checking the integrity of our flash-based BBT.
The modifications can be described by this new policy:
*) On any uncorrected ECC error, we invalidate the corresponding table
and retry our version-checking integrity logic.
*) On corrected bitflips, we mark both tables for re-writing to flash
(a.k.a. scrubbing).
Current integrity checks (i.e., comparing version numbers, etc.) should
take care of all the cases that result in rescanning the device for bad
blocks or falling back to the BBT as found in the mirror descriptor.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Instead of just printing a warning when encountering ECC errors, we
should return a proper error status and print a more informative
warning. Later, we will handle these error messages in the upper layers
of the BBT scan.
Note that this patch makes our check for ECC error codes a little bit
more restrictive, leaving all unrecognized errors to the generic "else"
clause. This shouldn't cause problems and could even be a benefit.
This code is based on some findings reported by Matthieu Castet.
Reported-by: Matthieu CASTET <matthieu.castet@parrot.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
This is a second step in restructuring `check_create()'. When we don't
rely on goto statements for our main functionality, the code will become
a little easier to manipulate.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
We will begin restructuring the code for check_create so that we can
make some important changes. For now, we should just begin to get rid of
some goto statements to make things cleaner. This is the first step of a
few, which are separated to make them easier to follow.
This step should just be a code refactor.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Remove some extra spaces
Consistently use '0x' prefix for bitfield-like constants
Spelling: "aplies" -> "applies"
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
`writeops' is unnecessary in the function `nand_update_bbt()'
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
There are a few reasons not to ignore ECC errors here.
First, mtd->read_oob is being called in raw mode, so there should be no
error correction in the first place.
Second, if we change this such that there *is* error correction in this
function, then we will want to pass the error message upward.
In fact, the code I introduced to "ignore ECC errors" would have been
better if it had just placed this test down in `scan_block_full()' in
the first place. We would like to ignore ECC errors when we are simply
checking for bad block markers (e.g., factory marked), but we may not
want to ignore ECC errors when scanning OOB for a flash-based BBT
pattern (in `scan_read_raw()'; note that the return codes from
`scan_read_raw()' are not actually handled yet).
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
A few pieces of code are unnecessarily duplicated. For easier
maintenance, we should fix this.
This should have no functional effect.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
These modes are not necessarily for OOB only. Particularly, MTD_OOB_RAW
affected operations on in-band page data as well. To clarify these
options and to emphasize that their effect is applied per-operation, we
change the primary prefix to MTD_OPS_.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Start moving away from the MTD_DEBUG_LEVEL messages. The dynamic
debugging feature is a generic kernel feature that provides more
flexibility.
(See Documentation/dynamic-debug-howto.txt)
Also fix some punctuation, indentation, and capitalization that went
along with the affected lines.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
This is a cleanup of some punctuation, indentation, and capitalization
on the lines affected affected by the last patch.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Instead of directly calling printk, it's simpler to use the built-in
pr_* functions. This shortens code and allows easy customization through
the definition of a pr_fmt() macro (not used currently). Ideally, we
could implement much of this with dev_* functions, but the MTD subsystem
does not necessarily register all its master `mtd_info.dev` device, so
we cannot use dev_* consistently. See:
http://lists.infradead.org/pipermail/linux-mtd/2011-July/036950.html
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Soon we will change many printk statements into pr_* statements, i.e.,
'printk(KERN_INFO, ...)' becomes 'pr_info(...)'. However, this means that
KERN_DEBUG messages will become pr_debug() statements and therefore will
not be activated by default - they must be enabled using dynamic debug.
So, for important DEBUG messages, we will simply upgrade these to INFO
so that they appear by default.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Now that nand_do_readoob() may return -EUCLEAN or -EBADMSG on ECC errors,
we need to handle the return value specially in some cases.
When scanning for simple bad block markers, reacting to an ECC error is
not very useful, as we assume that the relevant markers are still
non-0xFF for true bad blocks.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <dedekind1@gmail.com>
When a memory allocation fails, the kernel will print out a backtrace
automatically. These print statements are unnecessary.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Artem: while on it, do other commentaries clean-ups:
1. Start one-line comments with capital letter and no dot at the end
2. Turn sparse multi-line comments into one-line comments
3. Change "phrase ?" to "phrase?" and the same with "!".
4. Remove tabs from the kerneldoc parameters comments - they are mixed
with tabs often, and inconsistent.
5. Put dot at the end of descriptions in kerneldoc comments.
6. Some other small commentaries clean-ups
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
According to our new prefix rules, we should rename NAND_CREATE_EMPTY_BBT
with a NAND_BBT prefix, i.e., NAND_BBT_CREATE_EMPTY.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
The NAND_CREATE_EMPTY_BBT flag was added by commit:
453281a973
mtd: nand: introduce NAND_CREATE_EMPTY_BBT
This flag is not used within the kernel and not explained well, so I
took the liberty to edit its comments.
Also, this is a BBT-related flag (and closely tied with NAND_BBT_CREATE)
so I'm moving it to bbm.h next to NAND_BBT_CREATE, thus requiring that
we use the flag in nand_chip.bbt_options, *not* in nand_chip.options.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Recall the recently added prefix requirements:
* "NAND_" for flags in nand.h, used in nand_chip.options
* "NAND_BBT_" for flags in bbm.h, used in nand_chip.bbt_options
or in nand_bbt_descr.options
Thus, I am changing NAND_USE_FLASH_BBT to NAND_BBT_USE_FLASH.
Again, this flag is found in bbm.h and so should NOT be used in the
"nand_chip.options" field.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch works with the following three flags from two headers (nand.h
and bbm.h):
(1) NAND_USE_FLASH_BBT (nand.h)
(2) NAND_USE_FLASH_BBT_NO_OOB (nand.h)
(3) NAND_BBT_NO_OOB (bbm.h)
These flags are all related and interdependent, yet they were in
different headers. Flag (2) is simply the combination of (1) and (3) and
can be eliminated.
This patch accomplishes the following:
* eliminate NAND_USE_FLASH_BBT_NO_OOB (i.e., flag (2))
* move NAND_USE_FLASH_BBT (i.e., flag (1)) to bbm.h
It's important to note that because (1) and (3) are now both found in
bbm.h, they should NOT be used in the "nand_chip.options" field.
I removed a small section from the mtdnand DocBook because it referes to
NAND_USE_FLASH_BBT in nand.h, which has been moved to bbm.h.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch handles the problems we've been having with using conflicting
flags from nand.h and bbm.h in the same nand_chip.options field. We
should try to separate these two spaces a little more clearly, and so I
have added a bbt_options field to nand_chip.
Important notes about nand_chip fields:
* bbt_options field should contain ONLY flags from bbm.h. They should be
able to pass safely to a nand_bbt_descr data structure.
- BBT option flags start with the "NAND_BBT_" prefix.
* options field should contian ONLY flags from nand.h. Ideally, they
should not be involved in any BBT related options.
- NAND chip option flags start with the "NAND_" prefix.
* Every flag should have a nice comment explaining what the flag is. While
this is not yet the case on all existing flags, please be sure to write
one for new flags. Even better, you can help document the code better
yourself!
Please try to follow these conventions to make everyone's lives easier.
Among the flags that are being moved to the new bbt_options field
throughout various drivers, etc. are:
* NAND_BBT_SCANLASTPAGE
* NAND_BBT_SCAN2NDPAGE
and there will be more to come.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch reverts most of:
commit 58373ff0af
mtd: nand: more BB Detection refactoring and dynamic scan options
According to the discussion at:
http://lists.infradead.org/pipermail/linux-mtd/2011-May/035696.html
the NAND_BBT_SCANBYTE1AND6 flag, although technically valid, can break
some existing ECC layouts that use the 6th byte in the OOB for ECC data.
Furthermore, we apparently do not need to scan both bytes 1 and 6 in
the OOB region of the devices under consideration; instead, we only need
to scan one or the other.
Thus, the NAND_BBT_SCANBYTE1AND6 flag is at best unnecessary and at
worst a regression.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
It is nicer to dynamically create our badblock patterns than to
statically define them. The nand_create_default_bbt_descr() function
does a sufficient job of handling various bad block scanning options
for either flash-based or non-flash-based BBTs, so we might as well
use the function for both cases.
This patch simplifies and shortens our code (and removes a TODO that
I left a few months ago).
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
In 'verify_bbt_descr()', first check the "bd" pointer, then
dereference it.
Comments amended by Artem.
Signed-off-by: Stanislav Fomichev <kernel@fomichev.me>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Warning(include/linux/mtd/nand.h:543): No description found for parameter 'badblockbits'
Warning(drivers/mtd/nand/nand_bbt.c:1101): No description found for parameter 'mtd'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
it will create an empty BBT table without considering vendor's BBT
information. Vendor's information may be unavailable if the NAND
controller has a different DATA & OOB layout or this information may be
allready purged.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The first (sixt) byte in the OOB area contains vendor's bad block
information. During identification of the NAND chip this information is
collected by scanning the complete chip.
The option NAND_USE_FLASH_BBT is used to store this information in a sector so
we don't have to scan the complete flash. Unfortunately the code stores
a marker in order to recognize the BBT in the OOB area. This will fail
if the OOB area is completely used for ECC.
This patch introduces the option NAND_USE_FLASH_BBT_NO_OOB which has to be
used with NAND_USE_FLASH_BBT. It will then store BBT on flash without
touching the OOB area. The BBT format on flash remains same except the
first page starts with the recognition pattern followed by the version byte.
This change was tested in nandsim and it looks good so far :)
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
No code change.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This is a revision to PATCH 2/2 that I sent. Link:
http://lists.infradead.org/pipermail/linux-mtd/2010-July/030911.html
Added new flag for scanning of both bytes 1 and 6 of the OOB for
a BB marker (instead of simply one or the other).
The "check_pattern" and "check_short_pattern" functions were updated
to include support for scanning the two different locations in the OOB.
In order to handle increases in variety of necessary scanning patterns,
I implemented dynamic memory allocation of nand_bbt_descr structs
in new function 'nand_create_default_bbt_descr()'. This replaces
some increasingly-unwieldy, statically-declared descriptors. It can
replace several more (e.g. "flashbased" structs). However, I do not
test the flashbased options personally.
How this was tested:
I referenced 30+ data sheets (covering 100+ parts), and I tested a
selection of 10 different chips to varying degrees. Particularly, I
tested the creation of bad-block descriptors and basic BB scanning on
three parts:
ST NAND04GW3B2D, 2K page
ST NAND128W3A, 512B page
Samsung K9F1G08U0A, 2K page
To test these, I wrote some fake bad block markers to the flash (in OOB
bytes 1, 6, and elsewhere) to see if the scanning routine would detect
them properly. However, this method was somewhat limited because the
driver I am using has some bugs in its OOB write functionality.
Signed-off-by: Brian Norris <norris@broadcom.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Some level of support for various scanning locations was already built in,
but this required clean-up. First, BB marker location cannot be determined
_only_ by the page size. Instead, I implemented some heuristic detection
based on data sheets from various manufacturers (all found in
nand_base.c:nand_get_flash_type()).
Second, once these options were identified, they were not handled properly
by nand_bbt.c:nand_default_bbt(). I updated the static nand_bbt_desc structs
to reflect the need for more combinations of detection. The memory allocation
here probably needs to be done dynamically in the very near future (see next
patches).
Signed-off-by: Brian Norris <norris@broadcom.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
NAND_BB_LAST_PAGE used to be in nand.h, but it pertained to bad block
management and so belongs next to NAND_BBT_SCAN2NDPAGE in bbm.h. Also,
its previous flag value (0x00000400) conflicted with NAND_BBT_SCANALLPAGES
so I changed its value to 0x00008000. All uses of the name were modified to
provide consistency with other "NAND_BBT_*" flags.
Signed-off-by: Brian Norris <norris@broadcom.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This is a slightly modified version of a patch submitted last year by
Reuben Dowle <reuben.dowle@navico.com>. His original comments follow:
This patch adds support for some MLC NAND flashes that place the BB
marker in the LAST page of the bad block rather than the FIRST page used
for SLC NAND and other types of MLC nand.
Lifted from Samsung datasheet for K9LG8G08U0A (1Gbyte MLC NAND):
"
Identifying Initial Invalid Block(s)
All device locations are erased(FFh) except locations where the initial
invalid block(s) information is written prior to shipping. The initial
invalid block(s) status is defined by the 1st byte in the spare area.
Samsung makes sure that the last page of every initial invalid block has
non-FFh data at the column address of 2,048.
...
"
As far as I can tell, this is the same for all Samsung MLC nand, and in
fact the samsung bsp for the processor used in our project (s3c6410)
actually contained a hack similar to this patch but less portable to
enable use of their NAND parts. I discovered this problem when trying to
use a Micron NAND which does not used this layout - I wish samsung would
put their stuff in main-line to avoid this type of problem.
Currently this patch causes all MLC nand with manufacturer codes from
Samsung and ST(Numonyx) to use this alternative location, since these
are the manufactures that I know of that use this layout.
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This changes the behavier of MTD_OOB_RAW. It used to read both OOB and
data to the data buffer, however you would still need to specify the
dummy oob buffer.
This is only used in one place, but makes it hard to read data+oob
without ECC test, thus I removed that behavier, and fixed the user.
Now MTD_OOB_RAW behaves just like MTD_OOB_PLACE, but doesn't do ECC
validation
Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
MTD internal API presently uses 32-bit values to represent
device size. This patch updates them to 64-bits but leaves
the external API unchanged. Extending the external API
is a separate issue for several reasons. First, no one
needs it at the moment. Secondly, whether the implementation
is done with IOCTLs, sysfs or both is still debated. Thirdly
external API changes require the internal API to be accepted
first.
Note that although the MTD API will be able to support 64-bit
device sizes, existing drivers do not and are not required
to do so, although NAND base has been updated.
In general, changing from 32-bit to 64-bit values cause little
or no changes to the majority of the code with the following
exceptions:
- printk message formats
- division and modulus of 64-bit values
- NAND base support
- 32-bit local variables used by mtdpart and mtdconcat
- naughtily assuming one structure maps to another
in MEMERASE ioctl
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Once upon a time, the MTD repository was using CVS.
This patch therefore removes all usages of the no longer updated CVS
keywords from the MTD code.
This also includes code that printed them to the user.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
As was discussed between Ricard Wanderlöf, David Woodhouse, Artem
Bityutskiy and me, the current API for reading/writing OOB is confusing.
The thing that introduces confusion is the need to specify ops.len
together with ops.ooblen for reads/writes that concern only OOB not data
area. So, ops.len is overloaded: when ops.datbuf != NULL it serves to
specify the length of the data read, and when ops.datbuf == NULL, it
serves to specify the full OOB read length.
The patch inlined below is the slightly updated version of the previous
patch serving the same purpose, but with the new Artem's comments taken
into account.
Artem, BTW, thanks a lot for your valuable input!
Signed-off-by: Vitaly Wool <vwool@ru.mvista.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
The raw read/write access to NAND (without ECC) has been changed in the
NAND rework. Expose the new way - setting the file mode via ioctl - to
userspace. Also allow to read out the ecc statistics information so userspace
tools can see that bitflips happened and whether errors where correctable
or not. Also expose the number of bad blocks for the partition, so nandwrite
can check if the data fits into the parition before writing to it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Hopefully the last iteration on this!
The handling of out of band data on NAND was accompanied by tons of fruitless
discussions and halfarsed patches to make it work for a particular
problem. Sufficiently annoyed by I all those "I know it better" mails and the
resonable amount of discarded "it solves my problem" patches, I finally decided
to go for the big rework. After removing the _ecc variants of mtd read/write
functions the solution to satisfy the various requirements was to refactor the
read/write _oob functions in mtd.
The major change is that read/write_oob now takes a pointer to an operation
descriptor structure "struct mtd_oob_ops".instead of having a function with at
least seven arguments.
read/write_oob which should probably renamed to a more descriptive name, can do
the following tasks:
- read/write out of band data
- read/write data content and out of band data
- read/write raw data content and out of band data (ecc disabled)
struct mtd_oob_ops has a mode field, which determines the oob handling mode.
Aside of the MTD_OOB_RAW mode, which is intended to be especially for
diagnostic purposes and some internal functions e.g. bad block table creation,
the other two modes are for mtd clients:
MTD_OOB_PLACE puts/gets the given oob data exactly to/from the place which is
described by the ooboffs and ooblen fields of the mtd_oob_ops strcuture. It's
up to the caller to make sure that the byte positions are not used by the ECC
placement algorithms.
MTD_OOB_AUTO puts/gets the given oob data automaticaly to/from the places in
the out of band area which are described by the oobfree tuples in the ecclayout
data structre which is associated to the devicee.
The decision whether data plus oob or oob only handling is done depends on the
setting of the datbuf member of the data structure. When datbuf == NULL then
the internal read/write_oob functions are selected, otherwise the read/write
data routines are invoked.
Tested on a few platforms with all variants. Please be aware of possible
regressions for your particular device / application scenario
Disclaimer: Any whining will be ignored from those who just contributed "hot
air blurb" and never sat down to tackle the underlying problem of the mess in
the NAND driver grown over time and the big chunk of work to fix up the
existing users. The problem was not the holiness of the existing MTD
interfaces. The problems was the lack of time to go for the big overhaul. It's
easy to add more mess to the existing one, but it takes alot of effort to go
for a real solution.
Improvements and bugfixes are welcome!
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Modularize the write function and reorganaize the internal buffer
management. Remove obsolete chip options and fixup all affected
users.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
MTD clients are agnostic of FLASH which needs ECC suppport.
Remove the functions and fixup the callers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
