Subject: RE: [PATCH] net: ethernet: fs-enet: Use generic CRC32 implementation

From: David Laight <[email-masked]>
Date: Tue, 24 Jul 2018 11:05:59 +0000

From: Krzysztof Kozlowski
> Sent: 23 July 2018 17:20
> Use generic kernel CRC32 implementation because it:
> 1. Should be faster (uses lookup tables),

Are you sure?
The lookup tables are unlikely to be in the data cache and
the 6 cache misses kill performance.
(Not that it particularly matters when setting up multicast hash tables).

> 2. Removes duplicated CRC generation code,
> 3. Uses well-proven algorithm instead of coding it one more time.
...
>=20
> Not tested on hardware.

Have you verified that the old and new functions give the
same result for a few mac addresses?
It is very easy to use the wrong bits in crc calculations
or generate the output in the wrong bit order.

=09David

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