@@ -34,6 +34,31 @@ static void single_bit_error_data(void *error_data, void *correct_data,
__change_bit_le(offset, error_data);
}
+static unsigned int random_ecc_bit(size_t size)
+{
+ unsigned int offset = random32() % (3 * BITS_PER_BYTE);
+
+ if (size == 256) {
+ /*
+ * Don't inject a bit error into the insignificant bits (16th
+ * and 17th bit) in ECC code for 256 byte data block
+ */
+ while (offset == 16 || offset == 17)
+ offset = random32() % (3 * BITS_PER_BYTE);
+ }
+
+ return offset;
+}
+
+static void single_bit_error_ecc(void *error_ecc, void *correct_ecc,
+ size_t size)
+{
+ unsigned int offset = random_ecc_bit(size);
+
+ memcpy(error_ecc, correct_ecc, 3);
+ __change_bit_le(offset, error_ecc);
+}
+
static void no_bit_error(void *error_data, void *error_ecc,
void *correct_data, void *correct_ecc, const size_t size)
{
@@ -62,6 +87,13 @@ static void single_bit_error_in_data(void *error_data, void *error_ecc,
memcpy(error_ecc, correct_ecc, 3);
}
+static void single_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);
+ single_bit_error_ecc(error_ecc, correct_ecc, size);
+}
+
static int single_bit_error_correct(void *error_data, void *error_ecc,
void *correct_data, const size_t size)
{
@@ -87,6 +119,11 @@ static const struct nand_ecc_test nand_ecc_test[] = {
.prepare = single_bit_error_in_data,
.verify = single_bit_error_correct,
},
+ {
+ .name = "single-bit-error-in-ecc-correct",
+ .prepare = single_bit_error_in_ecc,
+ .verify = single_bit_error_correct,
+ },
};
static void dump_data_ecc(void *error_data, void *error_ecc, void *correct_data,
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 <akinobu.mita@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: linux-mtd@lists.infradead.org Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> --- drivers/mtd/tests/mtd_nandecctest.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+)