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Date:   Thu, 7 Jan 2021 21:21:16 +0100
From:   Marek =?UTF-8?B?QmVow7pu?= <kabel@kernel.org>
To:     Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc:     Andrew Lunn <andrew@lunn.ch>,
        Pali =?UTF-8?B?Um9ow6Fy?= <pali@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Thomas Schreiber <tschreibe@gmail.com>,
        Heiner Kallweit <hkallweit1@gmail.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/3] net: sfp: add workaround for Realtek RTL8672 and
 RTL9601C chips
Message-ID: <20210107212116.44a2baea@kernel.org>
In-Reply-To: <20210107194549.GR1551@shell.armlinux.org.uk>
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On Thu, 7 Jan 2021 19:45:49 +0000
Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote:

> I think you're not reading the code very well. It checks for bytes at
> offset 1..blocksize-1, blocksize+1..2*blocksize-1, etc are zero. It
> does _not_ check that byte 0 or the byte at N*blocksize is zero - these
> bytes are skipped. In other words, the first byte of each transfer can
> be any value. The other bytes of the _entire_ ID must be zero.

Wouldn't it be better, instead of checking if 1..blocksize-1 are zero,
to check whether reading byte by byte returns the same as reading 16
bytes whole?

Marek