The NAND rework resulted in non ECC based reads. Fix it up and
do a bit of cleanup while at it.
Pointed out by Adrian Bunk.
Signed-off-by: Thomas Gleixner <[email protected]>
The other way round works not really well with boards which have a
static NAND chipselect.
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: David Woodhouse <[email protected]>
The rework of the command handling in the nand driver
led to wrong address setting in the command control
function. Use the correct address again.
Signed-off-by: Thomas Gleixner <[email protected]>
The oob fixups broke a return value and missed one patch from
the Mailing List.
Signed-off-by: Savin Zlobec <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Following problems are addressed:
- wrong status caused early break out of nand_wait()
- removed the bogus status check in nand_wait() which
is a relict of the abandoned support for interrupted
erase.
- status check moved to the correct place in read_oob
- oob support for syndrom based ecc with strange layouts
- use given offset in the AUTOOOB based oob operations
Partially based on a patch from Vitaly Vool <[email protected]>
Thanks to Savin Zlobec <[email protected]> for tracking down the
status problem.
Signed-off-by: Thomas Gleixner <[email protected]>
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 <[email protected]>
Return -EUCLEAN on read when a bitflip was detected and corrected, so the
clients can react and eventually copy the affected block to a spare one.
Make all in kernel users aware of the change.
Signed-off-by: Thomas Gleixner <[email protected]>
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 <[email protected]>
Most of those macros are unused and the used ones just obfuscate
the code. Remove them and fixup all users.
Signed-off-by: Thomas Gleixner <[email protected]>
The nand_oobinfo structure is not fitting the newer error correction
demands anymore. Replace it by struct nand_ecclayout and fixup the users
all over the place. Keep the nand_oobinfo based ioctl for user space
compability reasons.
Signed-off-by: Thomas Gleixner <[email protected]>
The info structure for out of band data was copied into
the mtd structure. Make it a pointer and remove the ability
to set it from userspace. The position of ecc bytes is
defined by the hardware and should not be changed by software.
Signed-off-by: Thomas Gleixner <[email protected]>
The platform structure was lacking an oobinfo field.
The NDFC driver had some remains from another tree.
Signed-off-by: Thomas Gleixner <[email protected]>
We have a type pointer. Make use of it instead of the error prone nand_ids[i]
reference.
The NAND driver used to set default name settings from the chip ID
string for the device. The feature got lost during the rework. Add it back.
Signed-off-by: Thomas Gleixner <[email protected]>
nCE setting can be done when the first command is issued to the device.
We keep the deselect functionality as it makes sense to deassert nCE
when the device becomes idle.
Signed-off-by: Thomas Gleixner <[email protected]>
Modularize the write function and reorganaize the internal buffer
management. Remove obsolete chip options and fixup all affected
users.
Signed-off-by: Thomas Gleixner <[email protected]>
Removing readv from struct mtd_info broke block2mtd. Remove the
reference and the useless default implementation.
Signed-off-by: Thomas Gleixner <[email protected]>
Split the core of the read function out and implement
seperate handling functions for software and hardware
ECC.
Signed-off-by: Thomas Gleixner <[email protected]>
Add read/write function pointers to struct nand_ecc_ctrl to
prepare the modulaization of nand_read/write functions. The
current implementation handles every type of ecc mode
software/hardware and all kinds of strange ecc placement
schemes in one switch/if construct. Thats too complex to
maintain and too inflexible to expand. Modularization will
also shorten the code pathes of the read/write functions.
Signed-off-by: Thomas Gleixner <[email protected]>
FLASH - especially NAND FLASH - will become less reliable
and bit flips more likely. Add an ECC statistics struct
to struct mtd_info to keep track of this.
Signed-off-by: Thomas Gleixner <[email protected]>
The nand driver has a superflous read ready / command
delay in the read functions. This was added to handle
chips which have an automatic read forward. Newer
chips do not have this functionality anymore. Add this
option to avoid the delay / I/O operation. Mark all
large page chips with the new option flag.
Signed-off-by: Thomas Gleixner <[email protected]>
The lock simplifying patch did not move the lock and waitqueue
initialization into the controller allocation patch.
This reinitializes waitqueue and spinlocks also for driver
supplied controller stuctures. Move it into the allocation path.
Signed-off-by: Thomas Gleixner <[email protected]>
The previous change of the command / hardware control allows to
remove the write_byte/word functions completely, as their only
user were nand_command and nand_command_lp.
Signed-off-by: Thomas Gleixner <[email protected]>
The hwcontrol function enforced a step by step state machine
for any kind of hardware chip access. Let the hardware driver
know which control bits are set and inform it about a change
of the control lines. Let the hardware driver write out the
command and address bytes directly. This gives a peformance
advantage for address bus controlled chips and simplifies the
quirks in the hardware drivers.
Signed-off-by: Thomas Gleixner <[email protected]>
MTD clients are agnostic of FLASH which needs ECC suppport.
Remove the functions and fixup the callers.
Signed-off-by: Thomas Gleixner <[email protected]>
First step of modularizing ECC support.
- Move ECC related functionality into a seperate embedded data structure
- Get rid of the hardware dependend constants to simplify new ECC models
Signed-off-by: Thomas Gleixner <[email protected]>
Seperate functionality out of nand_scan so the code is more
readable. No functional change. First step of simplifying
the nand driver.
Signed-off-by: Thomas Gleixner <[email protected]>
The NAND driver used a mix of unsigned char, u_char amd uint8_t
data types. Consolidate to uint8_t usage
Signed-off-by: Thomas Gleixner <[email protected]>
The writev based write buffer implementation was far to complex as
in most use cases the write buffer had to be handled anyway.
Simplify the write buffer handling and use mtd->write instead.
From extensive testing no performance impact has been noted.
Signed-off-by: Thomas Gleixner <[email protected]>
Replace the chip lock by a the controller lock. For simple drivers a
dummy controller structure is created by the scan code.
This simplifies the locking algorithm in nand_get/release_chip().
Signed-off-by: Thomas Gleixner <[email protected]>
Unrolling the loops produces denser and much faster code.
Add a config switch which allows to select the byte order of the
resulting ecc code. The current Linux implementation has a byte
swap versus the SmartMedia specification
Signed-off-by: Thomas Gleixner <[email protected]>
Thomas Gleixner