diff options
| author | Roger Knecht <roger@norberthealth.com> | 2022-05-21 14:47:45 +0200 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-06-07 10:27:38 +0200 |
| commit | 77991645952c21962a095910c51fe0f73d35bf91 (patch) | |
| tree | 390109e8afbf963abde0928317275fefb85c58db /include/linux/crc-itu-t.h | |
| parent | e71e60cd74df9386c3f684c54888f2367050b831 (diff) | |
| download | linux-77991645952c21962a095910c51fe0f73d35bf91.tar.bz2 | |
crc-itu-t: fix typo in CRC ITU-T polynomial comment
The code comment says that the polynomial is x^16 + x^12 + x^15 + 1, but
the correct polynomial is x^16 + x^12 + x^5 + 1. Quoting from page 2 in
the ITU-T V.41 specification [1]:
2 Encoding and checking process
The service bits and information bits, taken in conjunction,
correspond to the coefficients of a message polynomial having terms
from x^(n-1) (n = total number of bits in a block or sequence) down to
x^16. This polynomial is divided, modulo 2, by the generating
polynomial x^16 + x^12 + x^5 + 1.
The hex (truncated) polynomial 0x1021 and CRC code implementation are
correct, however.
[1] https://www.itu.int/rec/T-REC-V.41-198811-I/en
Signed-off-by: Roger Knecht <roger@norberthealth.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'include/linux/crc-itu-t.h')
| -rw-r--r-- | include/linux/crc-itu-t.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/crc-itu-t.h b/include/linux/crc-itu-t.h index a4367051e192..2f991a427ade 100644 --- a/include/linux/crc-itu-t.h +++ b/include/linux/crc-itu-t.h @@ -4,7 +4,7 @@ * * Implements the standard CRC ITU-T V.41: * Width 16 - * Poly 0x1021 (x^16 + x^12 + x^15 + 1) + * Poly 0x1021 (x^16 + x^12 + x^5 + 1) * Init 0 */ |