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Date: Sun, 18 Feb 2024 21:27:22 +0100
From: Christian Marangi <ansuelsmth@gmail.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: "Russell King (Oracle)" <linux@armlinux.org.uk>,
	Heiner Kallweit <hkallweit1@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Florian Fainelli <florian.fainelli@broadcom.com>,
	Broadcom internal kernel review list <bcm-kernel-feedback-list@broadcom.com>,
	Robert Marko <robimarko@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>,
	Nipun Gupta <nipun.gupta@amd.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Puneet Gupta <puneet.gupta@amd.com>,
	Abhijit Gangurde <abhijit.gangurde@amd.com>,
	Umang Jain <umang.jain@ideasonboard.com>, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [net-next RFC PATCH 1/6] net: phy: add support for defining
 multiple PHY IDs in PHY driver
References: <20240218190034.15447-1-ansuelsmth@gmail.com>
 <20240218190034.15447-2-ansuelsmth@gmail.com>
 <ZdJbciylnw8+ve8V@shell.armlinux.org.uk>
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 <829f8c7d-c09b-4264-818a-3f7b047ec44f@lunn.ch>
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On Sun, Feb 18, 2024 at 09:10:30PM +0100, Andrew Lunn wrote:
> > > > +	phy_dev_id = (struct mdio_device_id *)&phydev->dev_id;
> > > 
> > > Why this cast? Try to write code that doesn't need casts.
> > > 
> > 
> > This cast is needed to keep the dev_id const in the phy_device struct so
> > that other are warned to not modify it and should only be handled by
> > phy_probe since it's the one that fills it.
> > 
> > Alternative is to drop const and drop the warning.
> 
> Can you propagate the const. Make phy_dev_id point to a const?
>

Mhh not following, I tried changing to const struct mdio_device_id *phy_dev_id
but that results in memcpy complain (dest is void * not const) and
writing in read-only for the single PHY part (the else part)

An alternative might be to make dev_id a pointer in struct phy_device
and dynamically allocate a mdio_device_id for the case of single PHY
(else case). That effectively remove the need of this cast but I would
love to skip checking for -ENOMEM (this is why i made that local)

If it's OK to dynamically allocate for the else case then I will make
this change. I just tested this implementation and works correctly with
not warning.

-- 
	Ansuel