Received-SPF: pass (google.com: domain of linux-kernel+bounces-16034-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Precedence: bulk
MIME-Version: 1.0
References: <20231220045228.27079-2-luizluca@gmail.com> <ZZPtUIRerqTI2/yh@shell.armlinux.org.uk>
 <CAJq09z61JRNOBy6zLJ+D2pOVP-FCkofLjNghHSOkFJ=5q=6utQ@mail.gmail.com>
 <ZZU1SJlKpeU38c9I@shell.armlinux.org.uk> <ZZVMiPCoDyv/NZXN@shell.armlinux.org.uk>
In-Reply-To: <ZZVMiPCoDyv/NZXN@shell.armlinux.org.uk>
From: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Date: Wed, 3 Jan 2024 18:50:06 -0300
Message-ID: <CAJq09z56GmDhbZUWR_s+thOfu0WB47o66X3_Ko3KyTk44inMCg@mail.gmail.com>
Subject: Re: [PATCH net-next] net: mdio: get/put device node during (un)registration
To: "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc: kuba@kernel.org, netdev@vger.kernel.org, andrew@lunn.ch, 
	hkallweit1@gmail.com, davem@davemloft.net, edumazet@google.com, 
	pabeni@redhat.com, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"

> Please test to check that this addresses your issue. Thanks.
>
> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
> index 6cf73c15635b..afbad1ad8683 100644
> --- a/drivers/net/phy/mdio_bus.c
> +++ b/drivers/net/phy/mdio_bus.c
> @@ -193,6 +193,10 @@ static void mdiobus_release(struct device *d)
>              bus->state != MDIOBUS_ALLOCATED,
>              "%s: not in RELEASED or ALLOCATED state\n",
>              bus->id);
> +
> +       if (bus->state == MDIOBUS_RELEASED)
> +               fwnode_handle_put(dev_fwnode(d));
> +
>         kfree(bus);
>  }
>
> @@ -684,6 +688,15 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
>         bus->dev.groups = NULL;
>         dev_set_name(&bus->dev, "%s", bus->id);
>
> +       /* If the bus state is allocated, we're registering a fresh bus
> +        * that may have a fwnode associated with it. Grab a reference
> +        * to the fwnode. This will be dropped when the bus is released.
> +        * If the bus was set to unregistered, it means that the bus was
> +        * previously registered, and we've already grabbed a reference.
> +        */
> +       if (bus->state == MDIOBUS_ALLOCATED)
> +               fwnode_handle_get(dev_fwnode(&bus->dev));
> +
>         /* We need to set state to MDIOBUS_UNREGISTERED to correctly release
>          * the device in mdiobus_free()
>          *
> --

Thanks Russel. It is much better than my approach. You simply get/put
during registration/unregistration when a node is defined, no matter
who defined it (of_mdiobus_register or anything else). Clean and
simple.

Regards,

Luiz