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Date:   Mon, 19 Aug 2019 15:27:33 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Hubert Feurstein <h.feurstein@gmail.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Richard Cochran <richardcochran@gmail.com>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        "David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH net-next 2/3] net: dsa: mv88e6xxx: extend PTP gettime
 function to read system clock
Message-ID: <20190819132733.GE8981@lunn.ch>
References: <20190816163157.25314-1-h.feurstein@gmail.com>
 <20190816163157.25314-3-h.feurstein@gmail.com>
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> @@ -45,7 +45,8 @@ static int mv88e6xxx_smi_direct_write(struct mv88e6xxx_chip *chip,
>  {
>  	int ret;
>  
> -	ret = mdiobus_write_nested(chip->bus, dev, reg, data);
> +	ret = mdiobus_write_sts_nested(chip->bus, dev, reg, data,
> +				       chip->ptp_sts);
>  	if (ret < 0)
>  		return ret;
>  

Please also make a similar change to mv88e6xxx_smi_indirect_write().
The last write in that function should be timestamped.

Vivien, please could you think about these changes with respect to
RMU. We probably want to skip the RMU in this case, so we get slow but
uniform jitter, vs fast and unpredictable jitter from using the RMU.

Thanks
	Andrew