Date:   Sat, 4 Feb 2023 02:13:32 +0200
From:   Vladimir Oltean <olteanv@gmail.com>
To:     Oleksij Rempel <o.rempel@pengutronix.de>
Cc:     Woojung Huh <woojung.huh@microchip.com>,
        UNGLinuxDriver@microchip.com, Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, Wei Fang <wei.fang@nxp.com>,
        Heiner Kallweit <hkallweit1@gmail.com>, kernel@pengutronix.de,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        Arun.Ramadoss@microchip.com, intel-wired-lan@lists.osuosl.org
Subject: Re: [PATCH net-next v4 00/23] net: add EEE support for KSZ9477 and
 AR8035 with i.MX6
Message-ID: <20230204001332.dd4oq4nxqzmuhmb2@skbuf>
References: <20230201145845.2312060-1-o.rempel@pengutronix.de>
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On Wed, Feb 01, 2023 at 03:58:22PM +0100, Oleksij Rempel wrote:
> With this patch series we provide EEE control for KSZ9477 family of switches and
> AR8035 with i.MX6 configuration.
> According to my tests, on a system with KSZ8563 switch and 100Mbit idle link,
> we consume 0,192W less power per port if EEE is enabled.

What is the code flow through the kernel with EEE? I wasn't able to find
a good explanation about it.

Is it advertised by default, if supported? I guess phy_advertise_supported()
does that.

But is that desirable? Doesn't EEE cause undesired latency for MAC-level
PTP timestamping on an otherwise idle link?