From 6ed089c0a1bc6f371dbcf97fb4e8218deaa0ae17 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Sat, 8 Sep 2012 01:48:10 +0900 Subject: [PATCH] mtd: mtd_nandecctest: add double bit error detection tests 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 --- drivers/mtd/tests/mtd_nandecctest.c | 79 +++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) diff --git a/drivers/mtd/tests/mtd_nandecctest.c b/drivers/mtd/tests/mtd_nandecctest.c index caaeb64..b437fa4 100644 --- a/drivers/mtd/tests/mtd_nandecctest.c +++ b/drivers/mtd/tests/mtd_nandecctest.c @@ -48,6 +48,22 @@ static void single_bit_error_data(void *error_data, void *correct_data, __change_bit_le(offset, error_data); } +static void double_bit_error_data(void *error_data, void *correct_data, + size_t size) +{ + unsigned int offset[2]; + + offset[0] = random32() % (size * BITS_PER_BYTE); + do { + offset[1] = random32() % (size * BITS_PER_BYTE); + } while (offset[0] == offset[1]); + + memcpy(error_data, correct_data, size); + + __change_bit_le(offset[0], error_data); + __change_bit_le(offset[1], error_data); +} + static unsigned int random_ecc_bit(size_t size) { unsigned int offset = random32() % (3 * BITS_PER_BYTE); @@ -73,6 +89,21 @@ static void single_bit_error_ecc(void *error_ecc, void *correct_ecc, __change_bit_le(offset, error_ecc); } +static void double_bit_error_ecc(void *error_ecc, void *correct_ecc, + size_t size) +{ + unsigned int offset[2]; + + offset[0] = random_ecc_bit(size); + do { + offset[1] = random_ecc_bit(size); + } while (offset[0] == offset[1]); + + memcpy(error_ecc, correct_ecc, 3); + __change_bit_le(offset[0], error_ecc); + __change_bit_le(offset[1], error_ecc); +} + static void no_bit_error(void *error_data, void *error_ecc, void *correct_data, void *correct_ecc, const size_t size) { @@ -122,6 +153,39 @@ static int single_bit_error_correct(void *error_data, void *error_ecc, return -EINVAL; } +static void double_bit_error_in_data(void *error_data, void *error_ecc, + void *correct_data, void *correct_ecc, const size_t size) +{ + double_bit_error_data(error_data, correct_data, size); + memcpy(error_ecc, correct_ecc, 3); +} + +static void single_bit_error_in_data_and_ecc(void *error_data, void *error_ecc, + void *correct_data, void *correct_ecc, const size_t size) +{ + single_bit_error_data(error_data, correct_data, size); + single_bit_error_ecc(error_ecc, correct_ecc, size); +} + +static void double_bit_error_in_ecc(void *error_data, void *error_ecc, + void *correct_data, void *correct_ecc, const size_t size) +{ + memcpy(error_data, correct_data, size); + double_bit_error_ecc(error_ecc, correct_ecc, size); +} + +static int double_bit_error_detect(void *error_data, void *error_ecc, + void *correct_data, const size_t size) +{ + unsigned char calc_ecc[3]; + int ret; + + __nand_calculate_ecc(error_data, size, calc_ecc); + ret = __nand_correct_data(error_data, error_ecc, calc_ecc, size); + + return (ret == -1) ? 0 : -EINVAL; +} + static const struct nand_ecc_test nand_ecc_test[] = { { .name = "no-bit-error", @@ -138,6 +202,21 @@ static const struct nand_ecc_test nand_ecc_test[] = { .prepare = single_bit_error_in_ecc, .verify = single_bit_error_correct, }, + { + .name = "double-bit-error-in-data-detect", + .prepare = double_bit_error_in_data, + .verify = double_bit_error_detect, + }, + { + .name = "single-bit-error-in-data-and-ecc-detect", + .prepare = single_bit_error_in_data_and_ecc, + .verify = double_bit_error_detect, + }, + { + .name = "double-bit-error-in-ecc-detect", + .prepare = double_bit_error_in_ecc, + .verify = double_bit_error_detect, + }, }; static void dump_data_ecc(void *error_data, void *error_ecc, void *correct_data, -- 2.7.4