From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Lunn <andrew@lunn.ch>
Subject: Re: [PATCH v3 3/4] net: nb8800: Move HW init to ndo_open()
Date: Thu, 16 Nov 2017 17:23:49 +0100
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Cc: netdev <netdev@vger.kernel.org>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Mason <slash.tmp@free.fr>,
        Thibaud Cornic <thibaud_cornic@sigmadesigns.com>,
        Mans Rullgard <mans@mansr.com>,
        David Miller <davem@davemloft.net>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>
To: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
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> I'm starting to think there is some kind of race condition between
> SW and HW handling of descriptors. This might also explain the
> out-of-order warnings.

Hi Marc

Maybe take a look at your memory barriers. Most accesses using the
_relaxed() version, i.e, no barrier. And then there are specific
barriers when needed. One could be missing.

As a quick test, drop the _relaxed. Force a barrier with each
access. If that works, it is a clear indication you have a barrier
problem.

	Andrew