Re: [PATCH v6 11/11] of: mdio: Prevent of_mdiobus_register from scanning mdio-mux nodes

From: Florian Fainelli
Date: Thu Sep 28 2017 - 00:50:56 EST




On 09/27/2017 07:12 AM, Andrew Lunn wrote:
> On Wed, Sep 27, 2017 at 09:34:14AM +0200, Corentin Labbe wrote:
>> Each child node of an MDIO node is scanned as a PHY when calling
>> of_mdiobus_register() givint the following result:
>> [ 18.175379] mdio_bus stmmac-0: /soc/ethernet@1c30000/mdio/mdio-mux has invalid PHY address
>> [ 18.175408] mdio_bus stmmac-0: scan phy mdio-mux at address 0
>> [ 18.175450] mdio_bus stmmac-0: scan phy mdio-mux at address 1
>> [...]
>> [ 18.176420] mdio_bus stmmac-0: scan phy mdio-mux at address 30
>> [ 18.176452] mdio_bus stmmac-0: scan phy mdio-mux at address 31
>>
>> Since mdio-mux nodes are not PHY, this patch a way to to not scan
>> them.
>
> Hi Corentin
>
> I still don't like this, but ...

Me neither, even more so as I don't understand the reasoning behind
putting the mux as a child node of the MDIO bus controller in the first
place.

Also, you need to re-order patches such that this patch comes before the
DTS changes.

>
>>
>> Signed-off-by: Corentin Labbe <clabbe.montjoie@xxxxxxxxx>
>> ---
>> drivers/of/of_mdio.c | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
>> index d94dd8b77abd..d90ddb0d90f2 100644
>> --- a/drivers/of/of_mdio.c
>> +++ b/drivers/of/of_mdio.c
>> @@ -190,6 +190,10 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
>> struct device_node *child;
>> bool scanphys = false;
>> int addr, rc;
>> + static const struct of_device_id do_not_scan[] = {
>> + { .compatible = "mdio-mux" },
>> + {}
>> + };
>
> Please rename this to some less generic. What i don't want is other
> compatible strings added here. We want to make the exception for
> muxes, but nothing else. So something like compatible_muxes?
>
> Andrew
>

--
Florian