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Date:   Tue, 23 Feb 2021 15:53:34 +0200
From:   Leon Romanovsky <leon@kernel.org>
To:     Kishon Vijay Abraham I <kishon@ti.com>
Cc:     Steen Hegelund <steen.hegelund@microchip.com>,
        Vinod Koul <vkoul@kernel.org>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Lars Povlsen <lars.povlsen@microchip.com>,
        Bjarni Jonasson <bjarni.jonasson@microchip.com>,
        Microchip UNG Driver List <UNGLinuxDriver@microchip.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Andrew Lunn <andrew@lunn.ch>
Subject: Re: [PATCH v15 2/4] phy: Add media type and speed serdes
 configuration interfaces
Message-ID: <YDUI3rYnNxhxiZem@unreal>
References: <20210218161451.3489955-1-steen.hegelund@microchip.com>
 <20210218161451.3489955-3-steen.hegelund@microchip.com>
 <YDH20a2hP+HtBqHz@unreal>
 <94dad8f439dd870b3488130e82f50e28b81fccf1.camel@microchip.com>
 <c1b78a32-de24-c036-5a7a-7ef297cc5e3a@ti.com>
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On Tue, Feb 23, 2021 at 05:52:14PM +0530, Kishon Vijay Abraham I wrote:
> Hi Leon,
>
> On 22/02/21 1:30 pm, Steen Hegelund wrote:
> > Hi Leon,
> >
> > On Sun, 2021-02-21 at 07:59 +0200, Leon Romanovsky wrote:
> >> EXTERNAL EMAIL: Do not click links or open attachments unless you
> >> know the content is safe
> >>
> >> On Thu, Feb 18, 2021 at 05:14:49PM +0100, Steen Hegelund wrote:
> >>> Provide new phy configuration interfaces for media type and speed
> >>> that
> >>> allows e.g. PHYs used for ethernet to be configured with this
> >>> information.
> >>>
> >>> Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com>
> >>> Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
> >>> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> >>> Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
> >>> ---
> >>>
> >
> > ...
> >
> >>> ?int phy_validate(struct phy *phy, enum phy_mode mode, int submode,
> >>> ?????????????? union phy_configure_opts *opts);
> >>> @@ -344,6 +356,20 @@ static inline int phy_set_mode_ext(struct phy
> >>> *phy, enum phy_mode mode,
> >>> ?#define phy_set_mode(phy, mode) \
> >>> ????? phy_set_mode_ext(phy, mode, 0)
> >>>
> >>> +static inline int phy_set_media(struct phy *phy, enum phy_media
> >>> media)
> >>> +{
> >>> +???? if (!phy)
> >>> +???????????? return 0;
> >>
> >> I'm curious, why do you check for the NULL in all newly introduced
> >> functions?
> >> How is it possible that calls to phy_*() supply NULL as the main
> >> struct?
> >>
> >> Thanks
> >
> > I do not know the history of that, but all the functions in the
> > interface that takes a phy as input and returns a status follow that
> > pattern.  Maybe Kishon and Vinod knows the origin?
>
> It is to make handling optional PHYs simpler. See here for the origin :-)
> http://lore.kernel.org/r/1391264157-2112-1-git-send-email-andrew@lunn.ch

Thanks for the pointer, it is good to know.
I personally would do it differently, but whatever.

>
> Thanks
> Kishon
> >
> >>
> >>> +???? return -ENODEV;
> >>> +}
> >>> +
> >>> +static inline int phy_set_speed(struct phy *phy, int speed)
> >>> +{
> >>> +???? if (!phy)
> >>> +???????????? return 0;
> >>> +???? return -ENODEV;
> >>> +}
> >>> +
> >>> ?static inline enum phy_mode phy_get_mode(struct phy *phy)
> >>> ?{
> >>> ????? return PHY_MODE_INVALID;
> >>> --
> >>> 2.30.0
> >>>
> >
> > Best Regards
> > Steen
> >