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Date:   Sun, 25 Oct 2020 15:47:22 +0100
From:   Andrew Lunn <andrew@lunn.ch>
To:     Tom Rix <trix@redhat.com>
Cc:     Xu Yilun <yilun.xu@intel.com>, jesse.brandeburg@intel.com,
        anthony.l.nguyen@intel.com, davem@davemloft.net, kuba@kernel.org,
        mdf@kernel.org, lee.jones@linaro.org, linux-kernel@vger.kernel.org,
        linux-fpga@vger.kernel.org, netdev@vger.kernel.org,
        lgoncalv@redhat.com, hao.wu@intel.com,
        Russ Weight <russell.h.weight@intel.com>
Subject: Re: [RFC PATCH 5/6] ethernet: dfl-eth-group: add DFL eth group
 private feature driver
Message-ID: <20201025144722.GF792004@lunn.ch>
References: <1603442745-13085-1-git-send-email-yilun.xu@intel.com>
 <1603442745-13085-6-git-send-email-yilun.xu@intel.com>
 <326cf423-33ef-1fea-86c5-1b5245eadddf@redhat.com>
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In-Reply-To: <326cf423-33ef-1fea-86c5-1b5245eadddf@redhat.com>
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> > +u64 read_mac_stats(struct eth_com *ecom, unsigned int addr)
> > +{
> > +	u32 data_l, data_h;
> > +
> > +	if (eth_com_read_reg(ecom, addr, &data_l) ||
> > +	    eth_com_read_reg(ecom, addr + 1, &data_h))
> > +		return 0xffffffffffffffffULL;

> return -1; ?

Since this is a u64 function, i expect you get a compiler
warning. Maybe only with W=1. It is better to use U64_MAX.

	 Andrew