The NAND_CHIPOPTIONS_MSK has limited utility and is causing real bugs. It
silently masks off at least one flag that might be set by the driver
(NAND_NO_SUBPAGE_WRITE). This breaks the GPMI NAND driver and possibly
others.

Really, as long as driver writers exercise a small amount of care with
NAND_* options, this mask is not necessary at all; it was only here to
prevent certain options from accidentally being set by the driver. But the
original thought turns out to be a bad idea occasionally. Thus, kill it.

Note, this patch fixes some major gpmi-nand breakage.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Tested-by: NHuang Shijie <shijie8@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Use the MTD_OPS_PLACE_OOB to replace the hard code "0".
Make the code more readable.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

There is an implemention of hardware ECC write page function which may return an
error indication.
For instance, using Atmel HW PMECC to write one page into a nand flash, the hardware
engine will compute the BCH ecc code for this page. so we need read a the
status register to theck whether the ecc code is generated.
But we cannot assume the status register always can be ready, for example,
incorrect hardware configuration or hardware issue, in such case we need
write_page() to return a error code.

Since the definition of 'write_page' function in struct nand_ecc_ctrl is 'void'.
So this patch will:
  1. add return 'int' value for 'write_page' function.
  2. to be consitent, add return 'int' value for 'write_page_raw' fuctions too.
  3. add code to test the return value, and if negative, indicate an
  error happend when write page with ECC.
  4. fix the compile warning in all impacted nand flash driver.

Note: I couldn't compile-test all of these easily, as some had ARCH dependencies.
Signed-off-by: NJosh Wu <josh.wu@atmel.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

According to its documentation, the NAND_NO_READRDY option is always used
when autoincrement is not supported. Autoincrement support was recently
dropped, so we can drop this options as well (defaulting to "no read ready
check").
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

As of edbc4540 [mtd: driver _read() returns max_bitflips; mtd_read()
returns -EUCLEAN], 'mtd->bitflip_threshold' must be set for mtd devices
having ECC, prior any 'mtd_read()' call.
Otherwise, 'mtd_read()' will falsely return -EUCLEAN.

Normally, 'mtd->bitflip_threshold' is initialized when the MTD is added.

However, this is too late for NAND MTDs, as 'scan_bbt()' is invoked
prior the existing initialization of 'mtd->bitflip_threshold'.

This is a problem since 'scan_bbt()' calls 'mtd_read()', in the case
of a flash-based bad block table.
It resulted in a falsely reported bitflips indication during BBT read,
which lead to constant scrubbing of the flash BBT blocks.

Initialize 'mtd->bitflip_threshold' to its default value (if not already
set by the driver), prior to invocation of 'scan_bbt()'.
Reported-by: NSascha Hauer <s.hauer@pengutronix.de>
Tested-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Apparently, there is an implementor of 'read_oob' which may return an
error inidication (e.g. docg4_read_oob may return -EIO).

Test the return value of 'read_oob/read_oob_raw', and if negative,
propagate the error, so it's returned by the '_read_oob' interface.
Signed-off-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

As of [mtd: nand: remove autoincrement 'sndcmd' code], the
NAND_CMD_READ0 command is issued unconditionally.

Thus, read_oob/read_oob_raw's 'sndcmd' argument is no longer needed, as
well as their return code.

Remove the 'sndcmd' parameter, and set the return code to 0.
Signed-off-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Don't read/write OOB if the caller doesn't require it.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

We now have an interface for notifying the nand_ecc_ctrl functions when OOB
data must be returned to the upper layers and when it may be left untouched.
This patch fills in the 'oob_required' parameter properly from
nand_do_{read,write}_ops. When utilized properly in the lower layers, this
parameter can improve performance and/or reduce complexity for NAND HW and SW
that can simply avoid transferring the OOB data.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: NJiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

New NAND controllers can perform read/write via HW engines which don't expose
OOB data in their DMA mode. To reflect this, we should rework the nand_chip /
nand_ecc_ctrl interfaces that assume that drivers will always read/write OOB
data in the nand_chip.oob_poi buffer. A better interface includes a boolean
argument that explicitly tells the callee when OOB data is requested by the
calling layer (for reading/writing to/from nand_chip.oob_poi).

This patch adds the 'oob_required' parameter to each relevant {read,write}_page
interface; all 'oob_required' parameters are left unused for now. The next
patch will set the parameter properly in the nand_base.c callers, and follow-up
patches will make use of 'oob_required' in some of the callee functions.

Note that currently, there is no harm in ignoring the 'oob_required' parameter
and *always* utilizing nand_chip.oob_poi, but there can be
performance/complexity/design benefits from avoiding filling oob_poi in the
common case. I will try to implement this for some drivers which can be ported
easily.

Note: I couldn't compile-test all of these easily, as some had ARCH
dependencies.

[dwmw2: Merge later 1/0 vs. true/false cleanup]
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: NJiandong Zheng <jdzheng@broadcom.com>
Acked-by: NMike Dunn <mikedunn@newsguy.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

No drivers use auto-increment NAND, so kill the NO_AUTOINCR option entirely.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The NAND_NO_AUTOINCR option is always set, so we will kill the option and make
"no autoincrement" the default behavior for nand_base.c. Thus, we should remove
the code which decides whether or not to send the NAND_CMD_READ0 command.
Instead, we unconditionally send the command.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The drivers' _read() method, absent an error, returns a non-negative integer
indicating the maximum number of bit errors that were corrected in any one
region comprising an ecc step.  MTD returns -EUCLEAN if this is >=
bitflip_threshold, 0 otherwise.  If bitflip_threshold is zero, the comparison is
not made since these devices lack ECC and always return zero in the non-error
case (thanks Brian)¹.  Note that this is a subtle change to the driver
interface.

This and the preceding patches in this set were tested with ubi on top of the
nandsim and docg4 devices, running the ubi test io_basic from mtd-utils.

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-March/040468.htmlSigned-off-by: NMike Dunn <mikedunn@newsguy.com>
Acked-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Ivan Djelic <ivan.djelic@parrot.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch adds sanity checks that ensure that drivers for controllers with
hardware ECC set the 'strength' element in struct nand_ecc_ctrl.  Also stylistic
changes to the line that calculates strength for software ECC.

This v2 simplifies the check.  Thanks Brian!¹

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-April/040890.htmlSigned-off-by: NMike Dunn <mikedunn@newsguy.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The ecc.read_page() method for nand drivers is changed to return the maximum
number of bitflips that were corrected on any one region covering an ecc step,
This patch doesn't change what the nand code returns to mtd.

This v2 includes the change to the fsl_ifc_nand driver requested by Scott¹.

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-April/040883.htmlSigned-off-by: NMike Dunn <mikedunn@newsguy.com>
Acked-by (freescale changes): Scott Wood <scottwood@freescale.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

ecc_strength element of mtd_info will be the strength of one ecc step, not of
the entire writesize, as was previously planned.  This is the appropriate way
because, as was pointed out¹, bit errors in excess of the strength of one
step can cause a hard error if they all occur within the same ecc region.

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-March/040313.htmlSigned-off-by: NMike Dunn <mikedunn@newsguy.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

To make sure the NAND chip is properly programmed we need a status
command before each page write. When CONFIG_MTD_NAND_VERIFY_WRITE=y this
assumption is broken when writing multiple pages consecutively. This
patch fixes this.
Signed-off-by: NBastian Hecht <hechtb@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Some not-supported nand chips may pass the current parsing code,
and get the wrong page size and oob size. Sometimes, it's hard to notice
that you get the wrong values, because there is no warning or error.

So it's useful to print out the page size and oob size in the end of
the parsing function. We can check these values with the datasheet of the nand
chip as soon as possible.

Artem: amend the print a bit
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Initialization of 'erase_info->fail_addr' to MTD_FAIL_ADDR_UNKNOWN prior
erase operation is duplicated accross several MTD drivers, and also taken
care of by some MTD users as well.

Harmonize it: initialize 'fail_addr' within 'mtd_erase()' interface.
Signed-off-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

With onfi a flash is organized into one or more logical units (LUNs).
A logical unit (LUN) is the minimum unit that can independently execute
commands and report status.

Mtd does not exploit LUN, so make it see a big single flash where size is
lun_size * number_of_lun.

Without this patch MT29F8G08ADBDAH4 size is 512MiB instead of 1GiB.

Artem: split long line on 2 shorter ones.
Signed-off-by: NMatthieu Castet <matthieu.castet@parrot.com>
Acked-by: NFlorian Fainelli <ffainelli@freebox.fr>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Flash device drivers initialize 'ecc_strength' in struct mtd_info, which is the
maximum number of bit errors that can be corrected in one writesize region.

Drivers using the nand interface intitialize 'strength' in struct nand_ecc_ctrl,
which is the maximum number of bit errors that can be corrected in one ecc step.
Nand infrastructure code translates this to 'ecc_strength'.

Also for nand drivers, the nand infrastructure code sets ecc.strength for ecc
modes NAND_ECC_SOFT, NAND_ECC_SOFT_BCH, and NAND_ECC_NONE.  It is set in the
driver for all other modes.
Signed-off-by: NMike Dunn <mikedunn@newsguy.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Some strange nand chip(such as Hynix H27UBG8T2A) can pass the `ONFI` signature
check. So the log can be printed out even it is not an ONFI nand indeed.

Change this log to the end of the function. Print out the log only when we
really detect an ONFI nand.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Acked-by: NFlorian Fainelli <ffainelli@freebox.fr>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

In many places in drivers we verify for the zero length, but this is very
inconsistent across drivers. This is obviously the right thing to do, though.
This patch moves the check to the MTD API functions instead and removes a lot
of duplication.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Reviewed-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

We already verify that offset and length are within the MTD device size
in the MTD API functions. Let's remove the duplicated checks in drivers.
This patch only affects the following API's:

'mtd_erase()'
'mtd_point()'
'mtd_unpoint()'
'mtd_get_unmapped_area()'
'mtd_read()'
'mtd_write()'
'mtd_panic_write()'
'mtd_lock()'
'mtd_unlock()'
'mtd_is_locked()'
'mtd_block_isbad()'
'mtd_block_markbad()'

This patch adds a bit of noise by removing too sparse empty lines, but this is
not too bad.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Currently, the flash-based BBT implementation writes bad block data only
to its flash-based table and not to the OOB marker area. Then, as new bad
blocks are marked over time, the OOB markers become incomplete and the
flash-based table becomes the only source of current bad block
information. This becomes an obvious problem when, for example:

 * bootloader cannot read the flash-based BBT format
 * BBT is corrupted and the flash must be rescanned for bad
   blocks; we want to remember bad blocks that were marked from Linux

So to keep the bad block markers in sync with the flash-based BBT, this
patch changes the default so that we write bad block markers to the proper
OOB area on each block in addition to flash-based BBT. Comments are
updated, expanded, and/or relocated as necessary.

The new flash-based BBT procedure for marking bad blocks:
 (1) erase the affected block, to allow OOB marker to be written cleanly
 (2) update in-memory BBT
 (3) write bad block marker to OOB area of affected block
 (4) update flash-based BBT
Note that we retain the first error encountered in (3) or (4), finish the
procedures, and dump the error in the end.

This should handle power cuts gracefully enough. (1) and (2) are mostly
harmless (note that (1) will not erase an already-recognized bad block).
The OOB and BBT may be "out of sync" if we experience power loss bewteen
(3) and (4), but we can reasonably expect that on next boot, subsequent
I/O operations will discover that the block should be marked bad again,
thus re-syncing the OOB and BBT.

Note that this is a change from the previous default flash-based BBT
behavior. If your system cannot support writing bad block markers to OOB,
use the new NAND_BBT_NO_OOB_BBM option (in combination with
NAND_BBT_USE_FLASH and NAND_BBT_NO_OOB).
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch renames all MTD functions by adding a "_" prefix:

mtd->erase -> mtd->_erase
mtd->read_oob -> mtd->_read_oob
...

The reason is that we are re-working the MTD API and from now on it is
an error to use MTD function pointers directly - we have a corresponding
API call for every pointer. By adding a leading "_" we achieve the following:

1. Make sure we convert every direct pointer users
2. A leading "_" suggests that this interface is internal and it becomes
   less likely that people will use them directly
3. Make sure all the out-of-tree modules stop compiling and the owners
   spot the big API change and amend them.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

As nand_default_block_markbad() is becoming more complex, it helps to
have code appear only in its relevant codepath(s). Here, the calculation
of `ofs' based on NAND_BBT_SCANLASTPAGE is only useful on paths where we
write bad block markers to OOB. We move the condition/calculation closer
to the `write' operation and update the comment to more correctly
describe the operation.

The variable `wr_ofs' is also used to help isolate our calculation of
the "write" offset from the usage of `ofs' to represent the eraseblock
offset. This will become useful when we reorder operations in the next
patch.

This patch should make no functional change.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

It seems that we have developed a bad-block-marking "feature" out of
pure laziness:

  "We write two bytes per location, so we dont have to mess with 16 bit
  access."

It's relatively simple to write a 1 byte at a time on x8 devices and 2
bytes at a time on x16 devices, so let's do it.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

nand_block_bad() doesn't check the correct pages when
NAND_BBT_SCAN2NDPAGE is enabled. It should scan both the OOB region of
both the 1st and 2nd page of each block.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Many NAND flash systems (especially those with MLC NAND) cannot be
reliably written twice in a row. For instance, when marking a bad block,
the block may already have data written to it, and so we should attempt
to erase the block before writing a bad block marker to its OOB region.

We can ignore erase failures, since the block may be bad such that it
cannot be erased properly; we still attempt to write zeros to its spare
area.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Funny one :) "Heck" fits somehow, too, but I am sure it was meant to be "Check".
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Our `ops' information was converted to a local variable recently, and
apparently, old code relied on the fact that the global version was
often left in a valid mode. We can't make this assumption on local
structs, and we shouldn't be relying on a previous state anyway.

Instead, we initialize mode to 0 for don't-care situations (i.e., the
operation does not use OOB anyway) and MTD_OPS_PLACE_OOB when we want to
place OOB data.

This fixes a bug with nand_default_block_markbad(), where we catch on
the BUG() call in nand_fill_oob():

Kernel bug detected[#1]:
...
Call Trace:
[<80307350>] nand_fill_oob.clone.5+0xa4/0x15c
[<803075d8>] nand_do_write_oob+0x1d0/0x260
[<803077c4>] nand_default_block_markbad+0x15c/0x1a8
[<802e8c2c>] part_block_markbad+0x80/0x98
[<802ebc74>] mtd_ioctl+0x6d8/0xbd0
[<802ec1a4>] mtd_unlocked_ioctl+0x38/0x5c
[<800d9c60>] do_vfs_ioctl+0xa4/0x6e4
[<800da2e4>] sys_ioctl+0x44/0xa0
[<8001381c>] stack_done+0x20/0x40
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

In rare cases, we are given an unaligned parameter `from' in
`nand_do_read_ops()'. In such cases, we use the page cache
(chip->buffers->databuf) as an intermediate buffer before dumping to the
client buffer. However, there are also cases where this buffer is not
cleanly reusable. In those cases, we need to make sure that we
explicitly invalidate the cache.

This patch prevents accidental reusage of the page cache, and for me,
this solves some problems I come across when reading a corrupted BBT
from flash (NAND_BBT_USE_FLASH and NAND_BBT_NO_OOB).

Note: the rare "unaligned" case is a result of the extra BBT pattern +
version located in the data area instead of OOB.

Also, this patch disables caching on raw reads, since we are reading
without error correction. This is, obviously, prone to errors and should
not be cached.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@intel.com>

The nand_chip.ops field is a struct that is passed around globally with
no particular reason. Every time it is used, it could just as easily be
replaced with a local struct that is updated on each operation. So make
it local.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem 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: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@intel.com>

This fixes issues with `nanddump -n' and the MEMREADOOB[64] ioctls on
hardware that performs error correction when reading only OOB data. A
driver for such hardware needs to know when we're doing a RAW vs. a
normal write, but mtd_do_read_oob does not pass such information to the
lower layers (e.g., NAND). We should pass MTD_OOB_RAW or MTD_OOB_PLACE
based on the MTD file mode.

For now, most drivers can get away with just setting:

  chip->ecc.read_oob_raw = chip->ecc.read_oob

This is done by default; but for systems that behave as described above,
you must supply your own replacement function.

This was tested with nandsim as well as on actual SLC NAND.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Cc: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@intel.com>

This fixes issues with `nandwrite -n -o' and the MEMWRITEOOB[64] ioctls
on hardware that writes ECC when writing OOB. The problem arises as
follows: `nandwrite -n' can write page data to flash without applying
ECC, but when used with the `-o' option, ECC is applied (incorrectly),
contrary to the `--noecc' option.

I found that this is the case because my hardware computes and writes
ECC data to flash upon either OOB write or page write. Thus, to support
a proper "no ECC" write, my driver must know when we're performing a raw
OOB write vs. a normal ECC OOB write. However, MTD does not pass any raw
mode information to the write_oob functions.  This patch addresses the
problems by:

1) Passing MTD_OOB_RAW down to lower layers, instead of just defaulting
   to MTD_OOB_PLACE
2) Handling MTD_OOB_RAW within the NAND layer's `nand_do_write_oob'
3) Adding a new (replaceable) function pointer in struct ecc_ctrl; this
   function should support writing OOB without ECC data. Current
   hardware often can use the same OOB write function when writing
   either with or without ECC

This was tested with nandsim as well as on actual SLC NAND.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Cc: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: NArtem 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: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem 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: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@intel.com>