From: Christian Eggers <ceggers@arri.de>
To: Vladimir Oltean <olteanv@gmail.com>
Cc: Richard Cochran <richardcochran@gmail.com>,
Florian Fainelli <f.fainelli@gmail.com>,
Andrew Lunn <andrew@lunn.ch>,
Vivien Didelot <vivien.didelot@gmail.com>,
Jakub Kicinski <kuba@kernel.org>,
Rob Herring <robh+dt@kernel.org>,
Helmut Grohne <helmut.grohne@intenta.de>,
Paul Barker <pbarker@konsulko.com>,
Codrin Ciubotariu <codrin.ciubotariu@microchip.com>,
George McCollister <george.mccollister@gmail.com>,
Marek Vasut <marex@denx.de>,
Tristram Ha <Tristram.Ha@microchip.com>,
"David S . Miller" <davem@davemloft.net>,
Woojung Huh <woojung.huh@microchip.com>,
"Microchip Linux Driver Support" <UNGLinuxDriver@microchip.com>,
<netdev@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH net-next 7/9] net: dsa: microchip: ksz9477: add hardware time stamping support
Date: Thu, 22 Oct 2020 13:11:40 +0200 [thread overview]
Message-ID: <2541271.Km786uMvHt@n95hx1g2> (raw)
In-Reply-To: <20201022105014.gflswfpie4qvbw3h@skbuf>
Hi Vladimir,
On Thursday, 22 October 2020, 12:50:14 CEST, Vladimir Oltean wrote:
> If the hardware supports p2p one-step, it subtracts the ingress time
> stamp value from the Pdelay_Request correction field. The user space
> software stack then simply copies the correction field into the
> Pdelay_Response, and on transmission the hardware adds the egress time
> stamp into the correction field.
>
> So we were correct about the behavior, just not about the target
> hardware.
>
> So, that's just not how this hardware works. What do you recommend?
> Keeping a FIFO of Pdelay_Req RX timestamps, and matching them to
> Pdelay_Resp messages on TX, all of that contained within tag_ksz.c?
after applying the RX timestamp correctly to the correction field (shifting
the nanoseconds by 16), it seems that "moving" the timestamp back to the tail
tag on TX is not required anymore. Keeping the RX timestamp simply in
the correction field (negative value), works fine now. So this halves the
effort in the tag_ksz driver.
Best regards
Christian
next prev parent reply other threads:[~2020-10-22 11:13 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-19 17:24 [RFC PATCH 0/9] net: dsa: microchip: PTP support for KSZ956x Christian Eggers
2020-10-19 17:24 ` [RFC PATCH net-next 1/9] dt-bindings: net: dsa: convert ksz bindings document to yaml Christian Eggers
2020-10-21 6:52 ` Kurt Kanzenbach
2020-10-21 8:46 ` Christian Eggers
2020-10-22 0:16 ` Vladimir Oltean
2020-10-22 0:40 ` Florian Fainelli
2020-10-22 10:54 ` Kurt Kanzenbach
2020-10-22 12:37 ` Vladimir Oltean
2020-10-22 19:17 ` Florian Fainelli
2020-10-26 13:54 ` Rob Herring
2020-10-19 17:24 ` [RFC PATCH net-next 2/9] net: dsa: microchip: split ksz_common.h Christian Eggers
2020-10-19 17:24 ` [RFC PATCH net-next 3/9] net: dsa: microchip: rename ksz9477.c to ksz9477_main.o Christian Eggers
2020-10-19 17:24 ` [RFC PATCH net-next 4/9] dt-bindings: net: dsa: microchip,ksz: add interrupt property Christian Eggers
2020-10-19 17:24 ` [RFC PATCH net-next 5/9] net: dsa: microchip: ksz9477: basic interrupt support Christian Eggers
2020-10-19 17:24 ` [RFC PATCH net-next 6/9] net: dsa: microchip: ksz9477: add Posix clock support for chip PTP clock Christian Eggers
2020-10-19 17:24 ` [RFC PATCH net-next 7/9] net: dsa: microchip: ksz9477: add hardware time stamping support Christian Eggers
2020-10-20 0:10 ` Vladimir Oltean
2020-10-20 8:39 ` Christian Eggers
2020-10-21 23:39 ` Vladimir Oltean
2020-10-22 2:42 ` Richard Cochran
2020-10-22 7:30 ` Christian Eggers
2020-10-22 10:17 ` Christian Eggers
2020-10-30 18:24 ` Vladimir Oltean
2020-11-01 9:35 ` Christian Eggers
2020-11-01 11:10 ` Vladimir Oltean
2020-11-01 22:14 ` Christian Eggers
2020-11-01 23:41 ` Vladimir Oltean
2020-11-01 23:55 ` Vladimir Oltean
2020-11-02 10:35 ` Christian Eggers
2020-11-02 12:28 ` Vladimir Oltean
2020-10-22 3:02 ` Richard Cochran
2020-10-22 9:01 ` Vladimir Oltean
2020-10-22 10:50 ` Vladimir Oltean
2020-10-22 11:11 ` Christian Eggers [this message]
2020-10-22 11:32 ` Vladimir Oltean
2020-10-22 14:34 ` Richard Cochran
2020-11-05 20:18 ` Christian Eggers
2020-11-10 1:42 ` Vladimir Oltean
2020-11-10 14:36 ` Christian Eggers
2020-11-10 16:40 ` Vladimir Oltean
2020-11-10 19:32 ` Vladimir Oltean
2020-11-11 21:49 ` Christian Eggers
2020-11-11 21:50 ` Christian Eggers
2020-11-12 15:28 ` Christian Eggers
2020-11-12 15:38 ` Vladimir Oltean
2020-11-17 11:27 ` Christian Eggers
2020-10-19 17:24 ` [RFC PATCH net-next 8/9] net: dsa: microchip: ksz9477: add Pulse Per Second (PPS) support Christian Eggers
2020-10-19 17:46 ` Vladimir Oltean
2020-10-20 8:38 ` Christian Eggers
2020-10-19 17:24 ` [RFC PATCH net-next 9/9] net: dsa: microchip: ksz9477: add periodic output support Christian Eggers
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