[PATCH v2 2/6] crypto: crc64 - add crc64-iso framework

[Elliott, Robert (Servers)]

> -----Original Message-----
> From: Kamlesh Gurudasani <kamlesh at ti.com>
> Sent: Friday, August 18, 2023 2:26 AM
> Subject: Re: [EXTERNAL] Re: [PATCH v2 2/6] crypto: crc64 - add crc64-iso
> framework
> 
> Eric Biggers <ebiggers at kernel.org> writes:
> 
> > Is "crc64-iso" clear enough, or should it be "crc64-iso3309"?  There are
> > thousands of ISO standards.  Different CRC variants are specified by
> different
> > ISO standards.  Is this particular variant indeed commonly referred to
> as simply
> > the "ISO" CRC-64?  Even if it's currently the case that all other CRCs
> in ISO
> > standards are different widths than 64 bits (which may be unlikely?),
> I'm not
> > sure we should count on no CRC-64 variant ever being standardized by
> ISO.
> >
> > - Eric
> https://en.wikipedia.org/wiki/Cyclic_redundancy_check
> 
> Last entry CRC-64-ISO in the table.
> It is mentioned as crc64-iso and that's the
> only 64-bit CRC standardized by ISO. 

ECMA-182 (DLT-1 tapes) was contributed to become ISO/IEC 13421 in 1993, so
that was another "64-bit CRC standardized by ISO." Plus, ISO could publish new
standards with new CRCs at any time.

> But I do agree that crc64-iso3309 would be more specific, will change it
> to crc64-iso3309 in next revision. Thanks.
> 
> Regards,
> Kamlesh

ISO-3309:1991 was withdrawn and revised by
ISO/IEC 3309:1993, which was withdrawn and revised by
ISO/IEC 13239:2002, which was confirmed in 2007 and is still current.

Apparently only the 1991 version defined a CRC-64; later versions dropped
that.

Is there really a demand for adding a 23 year old deprecated algorithm to
the kernel?