From: Andrew Lunn <andrew@lunn.ch>
To: Vivien Didelot <vivien.didelot@gmail.com>
Cc: Hubert Feurstein <h.feurstein@gmail.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Richard Cochran <richardcochran@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
Date: Mon, 19 Aug 2019 17:20:37 +0200 [thread overview]
Message-ID: <20190819152037.GH15291@lunn.ch> (raw)
In-Reply-To: <20190819111639.GB6123@t480s.localdomain>
On Mon, Aug 19, 2019 at 11:16:39AM -0400, Vivien Didelot wrote:
> On Mon, 19 Aug 2019 15:27:33 +0200, Andrew Lunn <andrew@lunn.ch> wrote:
> > > @@ -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.
>
> The RMU will have its own mv88e6xxx_bus_ops.
Yes, that is what i was expecting. But for this operation, triggering
a PTP timestamp, we probably want it to fall back to MDIO, which is
much more deterministic.
Andrew
next prev parent reply other threads:[~2019-08-19 15:20 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-16 16:31 [PATCH net-next 0/3] Improve phc2sys precision for mv88e6xxx switch in combination with imx6-fec Hubert Feurstein
2019-08-16 16:31 ` [PATCH net-next 1/3] net: mdio: add support for passing a PTP system timestamp to the mii_bus driver Hubert Feurstein
2019-08-17 3:30 ` Richard Cochran
2019-08-19 13:17 ` Andrew Lunn
2019-08-19 13:34 ` Vladimir Oltean
2019-08-19 13:37 ` Vladimir Oltean
2019-08-19 15:14 ` Andrew Lunn
2019-08-16 16:31 ` [PATCH net-next 2/3] net: dsa: mv88e6xxx: extend PTP gettime function to read system clock Hubert Feurstein
2019-08-19 13:27 ` Andrew Lunn
2019-08-19 15:16 ` Vivien Didelot
2019-08-19 15:20 ` Andrew Lunn [this message]
2019-08-19 17:14 ` Hubert Feurstein
2019-08-19 17:34 ` Andrew Lunn
2019-08-16 16:31 ` [PATCH net-next 3/3] net: fec: add support for PTP system timestamping for MDIO devices Hubert Feurstein
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