linux-stable.git/drivers/mtd/tests, branch v3.7.4

mtd: mtd_nandecctest: add double bit error detection tests

2012-09-29T14:48:02+00:00

This adds the double bit error detection test cases listed below:

* Prepare data block with double bit error and ECC data without
corruption, and verify that the uncorrectable error is detected by
__nand_correct_data().

* Prepare data block with single bit error and ECC data with single bit
error, and verify that the uncorrectable error is detected.

* Prepare data block without corruption and ECC data with double bit
error, and verify that the uncorrectable error is detected.

Signed-off-by: Akinobu Mita 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: mtd_nandecctest: add single bit error correction test

2012-09-29T14:47:55+00:00

This adds the single bit error correction test case listed below:

Prepare data block without corruption and ECC data with single bit error,
and verify that the data block is preserved by __nand_correct_data().

Signed-off-by: Akinobu Mita 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: mtd_nandecctest: add no corruption test

2012-09-29T14:47:45+00:00

This adds no corruptin test case listed below:

Prepare data block and ECC data with no corruption, and verify that
the data block is preserved by __nand_correct_data()

Signed-off-by: Akinobu Mita 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: mtd_nandecctest: rewrite the test routine

2012-09-29T14:47:37+00:00

This rewrites the entire test routine in order to make it easy to add more
tests by later changes and minimize duplication of each tests as much as
possible.

Now that each test is described by the members of struct nand_ecc_test:
- name: descriptive testname
- prepare: function to prepare data block and ecc with artifical corruption
- verify: function to verify the result of correcting data block

Signed-off-by: Akinobu Mita 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: mtd_nandecctest: support injecting bit error for ecc code

2012-09-29T14:47:28+00:00

Currently inject_single_bit_error() is used to inject single bit error
into randomly selected bit position of the 256 or 512 bytes data block.

Later change will add tests which inject bit errors into the ecc code.
Unfortunately, inject_single_bit_error() doesn't work for the ecc code
which is not a multiple of sizeof(unsigned long).

Because bit fliping at random position is done by __change_bit().
For example, flipping bit position 0 by __change_bit(0, addr) modifies
3rd byte (32bit) or 7th byte (64bit) on big-endian systems.

Using little-endian version of bitops can fix this issue.  But
little-endian version of __change_bit is not yet available.
So this defines __change_bit_le() locally in a similar fashion to
asm-generic/bitops/le.h and use it.

Signed-off-by: Akinobu Mita 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: tests: test for multi-bit error correction

2012-09-29T14:46:58+00:00

This tests ECC biterror recovery on a single NAND page. Mostly intended
to test ECC hardware and low-level NAND driver.

There are two test modes:

    0 - artificially inserting bit errors until the ECC fails
        This is the default method and fairly quick. It should
        be independent of the quality of the FLASH.

    1 - re-writing the same pattern repeatedly until the ECC fails.
        This method relies on the physics of NAND FLASH to eventually
        generate '0' bits if '1' has been written sufficient times. Depending
        on the NAND, the first bit errors will appear after 1000 or
        more writes and then will usually snowball, reaching the limits
        of the ECC quickly.

The test stops after 10000 cycles, should your FLASH be exceptionally
good and not generate bit errors before that. Try a different page
offset in that case.

Please note that neither of these tests will significantly 'use up' any FLASH
endurance. Only a maximum of two erase operations will be performed.

Signed-off-by: Iwo Mergler 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: mtd_nandecctest: ensure alignment requirement for bitops

2012-09-29T14:34:30+00:00

Currently the data blocks which is used to test single bit error
correction is allocated statically and injecting single bit error is
implemented by using __change_bit() which must operate on the memory
aligned to the size of an "unsigned long".  But there is no such
guarantee for statically allocated array.

This fix the issue by allocating the data block dynamically by
kmalloc().  It also allocate the ecc code dynamically instead of
allocating statically on stack.

The reason to allocate the ecc code dynamically is that later change
will add tests which inject bit errors into the ecc code by bitops.

Signed-off-by: Akinobu Mita 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: mtd_nandecctest: improve message output

2012-09-29T14:34:28+00:00

This includes the message related changes:

- Use pr_* instead of printk
- Print hexdump of ECC code if test fails
- Change log level for hexdump of data from KERN_DEBUG to KERN_INFO
- Factor out the hexdump code into a separate function

Signed-off-by: Akinobu Mita 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: mtd_nandecctest: make module_init() return appropriate errno

2012-09-29T14:34:25+00:00

Return -EINVAL instead of -1 (-EPERM) when test fails.

Signed-off-by: Akinobu Mita 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: mtd_nandecctest: remove unnecessary include

2012-09-29T14:34:22+00:00

Including linux/jiffies.h was required for calling srandom32(jiffies)
that has already been removed.

Signed-off-by: Akinobu Mita 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse