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Date:   Mon, 19 Jul 2021 10:14:09 +0200
From:   Martin Schiller <ms@dev.tdt.de>
To:     Hauke Mehrtens <hauke@hauke-m.de>
Cc:     Andrew Lunn <andrew@lunn.ch>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        f.fainelli@gmail.com, hkallweit1@gmail.com, linux@armlinux.org.uk,
        davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next v3] net: phy: intel-xway: Add RGMII internal
 delay configuration
Organization: TDT AG
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On 2021-07-17 18:38, Hauke Mehrtens wrote:
> On 7/13/21 3:06 PM, Andrew Lunn wrote:
>>>> [...]
>>>>> +#if IS_ENABLED(CONFIG_OF_MDIO)
>>>> is there any particular reason why we need to guard this with
>>>> CONFIG_OF_MDIO?
>>>> The dp83822 driver does not use this #if either (as far as I
>>>> understand at least)
>>>> 
>>> 
>>> It makes no sense to retrieve properties from the device tree if we 
>>> are
>>> compiling for a target that does not support a device tree.
>>> At least that is my understanding of this condition.
>> 
>> There should be stubs for all these functions, so if OF is not part of
>> the configured kernel, stub functions take their place. That has the
>> advantage of at least compiling the code, so checking parameter types
>> etc. We try to avoid #ifdef where possible, so we get better compiler
>> build test coverage. The more #ifef there are, the more different
>> configurations that need compiling in order to get build coverage.
>> 
>> 	       Andrew
>> 
> 
> The phy_get_internal_delay() function does not have a stub function
> directly, but it calls phy_get_int_delay_property() which has a stub,
> if CONFIG_OF_MDIO is not set, see:
> https://elixir.bootlin.com/linux/v5.14-rc1/source/drivers/net/phy/phy_device.c#L2797
> 
> The extra ifdef in the PHY driver only saves some code in the HY
> driver, but it should still work as before on systems without
> CONFIG_OF_MDIO.
> 
> I would also prefer to remove the ifdef from the intel-xway phy driver.
> 
> Hauke

OK, so I'll remove the ifdef from the driver.