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

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Date:   Tue, 24 Jul 2018 11:22:53 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Krzysztof Kozlowski' <krzk@...nel.org>
CC:     Pantelis Antoniou <pantelis.antoniou@...il.com>,
        "David S. Miller" <davem@...emloft.net>,
        "linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Eric Biggers <ebiggers3@...il.com>
Subject: RE: [PATCH] net: ethernet: fs-enet: Use generic CRC32 implementation

From: Krzysztof Kozlowski
> Sent: 24 July 2018 12:12
...
> >> 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.
> 
> I copied the original code and new one onto a different driver and run
> this in a loop for thousands of data input (although not all possible
> MAC combinations). The output was the same. I agree however that real
> testing would be important.

Since CRC are linear you only need to check that each input
bit generates the correct output.

	David

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