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Subject: Re: [PATCH v15 2/4] phy: Add media type and speed serdes
 configuration interfaces
To:     Steen Hegelund <steen.hegelund@microchip.com>,
        Leon Romanovsky <leon@kernel.org>
CC:     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>
References: <20210218161451.3489955-1-steen.hegelund@microchip.com>
 <20210218161451.3489955-3-steen.hegelund@microchip.com>
 <YDH20a2hP+HtBqHz@unreal>
 <94dad8f439dd870b3488130e82f50e28b81fccf1.camel@microchip.com>
From:   Kishon Vijay Abraham I <kishon@ti.com>
Message-ID: <c1b78a32-de24-c036-5a7a-7ef297cc5e3a@ti.com>
Date:   Tue, 23 Feb 2021 17:52:14 +0530
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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
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
>