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Date:   Wed, 26 Jan 2022 05:01:30 +0100
From:   Ansuel Smith <ansuelsmth@gmail.com>
To:     Florian Fainelli <f.fainelli@gmail.com>
Cc:     Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org
Subject: Re: [RFC PATCH v7 06/16] net: dsa: tag_qca: add define for handling
 mgmt Ethernet packet
Message-ID: <YfDHmpLxqUGWatQC@Ansuel-xps.localdomain>
References: <20220123013337.20945-1-ansuelsmth@gmail.com>
 <20220123013337.20945-7-ansuelsmth@gmail.com>
 <70a44baa-4a1c-9c9e-6781-b1b563c787bd@gmail.com>
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On Tue, Jan 25, 2022 at 07:54:15PM -0800, Florian Fainelli wrote:
> 
> 
> On 1/22/2022 5:33 PM, Ansuel Smith wrote:
> > Add all the required define to prepare support for mgmt read/write in
> > Ethernet packet. Any packet of this type has to be dropped as the only
> > use of these special packet is receive ack for an mgmt write request or
> > receive data for an mgmt read request.
> > A struct is used that emulates the Ethernet header but is used for a
> > different purpose.
> > 
> > Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> > ---
> 
> [snip]
> 
> > +/* Special struct emulating a Ethernet header */
> > +struct mgmt_ethhdr {
> > +	u32 command;		/* command bit 31:0 */
> > +	u32 seq;		/* seq 63:32 */
> > +	u32 mdio_data;		/* first 4byte mdio */
> > +	__be16 hdr;		/* qca hdr */
> > +} __packed;
> 
> Might be worth adding a BUILD_BUG_ON(sizeof(struct mgmt_ethhdr) !=
> QCA_HDR_MGMT_PKG_LEN) when you start making use of that structure?

Where should I put this check? Right after the struct definition,
correct? (I just checked definition of the macro)

> -- 
> Florian

-- 
	Ansuel