From: <Codrin.Ciubotariu@microchip.com>
To: <f.fainelli@gmail.com>, <andrew@lunn.ch>
Cc: <netdev@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <hkallweit1@gmail.com>,
<linux@armlinux.org.uk>, <davem@davemloft.net>
Subject: Re: [PATCH] net: mdio: of: Do not treat fixed-link as PHY
Date: Tue, 31 Mar 2020 08:54:13 +0000 [thread overview]
Message-ID: <bd9f2507-958e-50bf-2b84-c21adf6ab588@microchip.com> (raw)
In-Reply-To: <9bbbe2ed-985b-49e7-cc16-8b6bae3e8e8e@gmail.com>
On 30.03.2020 20:22, Florian Fainelli wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> On 3/30/2020 9:30 AM, Andrew Lunn wrote:
>> On Mon, Mar 30, 2020 at 07:01:36PM +0300, Codrin Ciubotariu wrote:
>>> Some ethernet controllers, such as cadence's macb, have an embedded MDIO.
>>> For this reason, the ethernet PHY nodes are not under an MDIO bus, but
>>> directly under the ethernet node. Since these drivers might use
>>> of_mdiobus_child_is_phy(), we should fix this function by returning false
>>> if a fixed-link is found.
>>
>> So i assume the problem occurs here:
>>
>> static int macb_mdiobus_register(struct macb *bp)
>> {
>> struct device_node *child, *np = bp->pdev->dev.of_node;
>>
>> /* Only create the PHY from the device tree if at least one PHY is
>> * described. Otherwise scan the entire MDIO bus. We do this to support
>> * old device tree that did not follow the best practices and did not
>> * describe their network PHYs.
>> */
>> for_each_available_child_of_node(np, child)
>> if (of_mdiobus_child_is_phy(child)) {
>> /* The loop increments the child refcount,
>> * decrement it before returning.
>> */
>> of_node_put(child);
>>
>> return of_mdiobus_register(bp->mii_bus, np);
>> }
>>
>> return mdiobus_register(bp->mii_bus);
>> }
>>
>> I think a better solution is
>>
>> for_each_available_child_of_node(np, child)
>> + if (of_phy_is_fixed_link(child)
>> + continue;
>> if (of_mdiobus_child_is_phy(child)) {
>> /* The loop increments the child refcount,
>> * decrement it before returning.
>> */
>> of_node_put(child);
>>
>> return of_mdiobus_register(bp->mii_bus, np);
>> }
>>
>> return mdiobus_register(bp->mii_bus);
>> }
>>
>> This problem is only an issue for macb, so keep the fix local to macb.
>
> Agree, there is no reason for of_mdiobus_child_is_phy() to be checking
> for a fixed-link. If you submit this formally:
>
> Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Thanks guys. I thought there might be other controllers that have the
PHY nodes inside the ethernet node. If not, I guess that
of_mdiobus_child_is_phy() can be restricted to be called only if the
passed device_node points to an MDIO node.
Moving the fix to macb, I think that of_phy_is_fixed_link() needs a
device_node to the ethernet node, since it also has to deal with the
legacy case in which fixed-link is a property, so it would look like
something like this:
struct device_node *child, *np = bp->pdev->dev.of_node;
+ if (of_phy_is_fixed_link(np))
+ return mdiobus_register(bp->mii_bus);
+
/* Only create the PHY from the device tree if at least one PHY is
I will send another patch shortly.
Thanks and best regards,
Codrin
next prev parent reply other threads:[~2020-03-31 8:54 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-30 16:01 [PATCH] net: mdio: of: Do not treat fixed-link as PHY Codrin Ciubotariu
2020-03-30 16:17 ` Andrew Lunn
2020-03-30 16:21 ` Russell King - ARM Linux admin
2020-03-30 16:24 ` Andrew Lunn
2020-03-30 16:30 ` Andrew Lunn
2020-03-30 17:22 ` Florian Fainelli
2020-03-31 8:54 ` Codrin.Ciubotariu [this message]
2020-03-31 12:59 ` Andrew Lunn
2020-04-01 7:50 ` Codrin.Ciubotariu
2020-04-01 13:06 ` Andrew Lunn
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