MIME-Version: 1.0
Date:   Fri, 10 Mar 2023 21:48:48 +0100
From:   Michael Walle <michael@walle.cc>
To:     Vladimir Oltean <vladimir.oltean@nxp.com>
Cc:     Horatiu Vultur <horatiu.vultur@microchip.com>,
        =?UTF-8?Q?K=C3=B6ry_Ma?= =?UTF-8?Q?incent?= 
        <kory.maincent@bootlin.com>, Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Heiner Kallweit <hkallweit1@gmail.com>, netdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-omap@vger.kernel.org,
        Maxime Chevallier <maxime.chevallier@bootlin.com>,
        Richard Cochran <richardcochran@gmail.com>,
        thomas.petazzoni@bootlin.com, Russell King <linux@armlinux.org.uk>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Jay Vosburgh <j.vosburgh@gmail.com>,
        Veaceslav Falico <vfalico@gmail.com>,
        Andy Gospodarek <andy@greyhouse.net>,
        Claudiu Manoil <claudiu.manoil@nxp.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        UNGLinuxDriver@microchip.com, Minghao Chi <chi.minghao@zte.com.cn>,
        Jie Wang <wangjie125@huawei.com>,
        Oleksij Rempel <linux@rempel-privat.de>,
        Sean Anderson <sean.anderson@seco.com>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>,
        Alexander Lobakin <alexandr.lobakin@intel.com>,
        Marco Bonelli <marco@mebeim.net>
Subject: Re: [PATCH v3 3/5] net: Let the active time stamping layer be
 selectable.
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Am 2023-03-10 17:06, schrieb Vladimir Oltean:
> On Fri, Mar 10, 2023 at 02:34:07PM +0100, Michael Walle wrote:
>> Yeah, but my problem right now is, that if this discussion won't find
>> any good solution, the lan8814 phy timestamping will find it's way
>> into an official kernel and then it is really hard to undo things.
>> 
>> So, I'd really prefer to *first* have a discussion how to proceed
>> with the PHY timestamping and then add the lan8814 support, so
>> existing boards don't show a regressions.
> 
> You don't mean LAN8814 but LAN8841, no?

Ohh, I'm stupid. No, I mean the LAN8814 (Quad PHY).

> For the former, PTP support was added in commit ece19502834d ("net: 
> phy:
> micrel: 1588 support for LAN8814 phy") - first present in v5.18.

Yeah and I remember.. there was some kind of issue with the PHY
latencies. Ok, looks like I'm screwed then. I wonder how Microchip
is doing it, because our board is almost an identical copy of the
reference system.

> For the latter, it was commit cafc3662ee3f ("net: micrel: Add PHC
> support for lan8841"), and this one indeed is in the v6.3 release
> candidates.
> 
> Assuming you can prove a regression, how about adding the PHY driver
> whitelist *without* the lan8841 as a patch to net.git? (blaming commit
> cafc3662ee3f ("net: micrel: Add PHC support for lan8841")).
> 
> Doing this will effectively deactivate lan8841 PHY timestamping without
> reverting the code. Then, this PHY timestamping support could be
> activated back in net-next, based on some sort of explicit UAPI call.

Sorry for the noise and any inconvenience,
-michael