linux-kernel - Re: [PATCH v2] net: stmmac: Use the right logging function in stmmac_mdio

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Date:   Thu, 10 Aug 2017 16:43:19 +0200
From:   Romain Perier <romain.perier@...labora.com>
To:     Andrew Lunn <andrew@...n.ch>
Cc:     Giuseppe Cavallaro <peppe.cavallaro@...com>,
        Alexandre Torgue <alexandre.torgue@...com>,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] net: stmmac: Use the right logging function in
 stmmac_mdio_register

Hi Andrew,


Le 10/08/2017 à 15:56, Andrew Lunn a écrit :
> On Thu, Aug 10, 2017 at 09:38:26AM +0200, Romain Perier wrote:
>> Currently, the function stmmac_mdio_register() is only used by
>> stmmac_dvr_probe() from stmmac_main.c, in order to register the MDIO bus
>> and probe information about the PHY. As this function is called before
>> calling register_netdev(), all messages logged from stmmac_mdio_register
>> are prefixed by "(unnamed net_device)". The goal of netdev_info or
>> netdev_err is to dump useful infos about a net_device, when this data
>> structure is partially initialized, there is no point for using these
>> functions.
>>
>> This commit fixes the issue by replacing all netdev_*() by the
>> corresponding dev_*() function for logging. The last netdev_info is
>> replaced by phy_attached_info(), as a valid phydev can be used at this
>> point.
>>
>> Signed-off-by: Romain Perier <romain.perier@...labora.com>
>> ---
>>
>> Changes in v2:
>> - Replaced dev_info() by phy_attached_print()
>> - Simplified message because informations were redudant
>> - Updated commit message
>>
>>  drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c | 11 ++++++-----
>>  1 file changed, 6 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>> index db157a47000c..e0fbf8657103 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>> @@ -204,6 +204,7 @@ int stmmac_mdio_register(struct net_device *ndev)
>>  	struct stmmac_priv *priv = netdev_priv(ndev);
>>  	struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
>>  	struct device_node *mdio_node = priv->plat->mdio_node;
>> +	struct device *dev = ndev->dev.parent;
>>  	int addr, found;
>>  
>>  	if (!mdio_bus_data)
>> @@ -237,7 +238,7 @@ int stmmac_mdio_register(struct net_device *ndev)
>>  	else
>>  		err = mdiobus_register(new_bus);
>>  	if (err != 0) {
>> -		netdev_err(ndev, "Cannot register the MDIO bus\n");
>> +		dev_err(dev, "Cannot register the MDIO bus\n");
>>  		goto bus_register_fail;
>>  	}
>>  
>> @@ -285,14 +286,14 @@ int stmmac_mdio_register(struct net_device *ndev)
>>  			irq_str = irq_num;
>>  			break;
>>  		}
>> -		netdev_info(ndev, "PHY ID %08x at %d IRQ %s (%s)%s\n",
>> -			    phydev->phy_id, addr, irq_str, phydev_name(phydev),
>> -			    act ? " active" : "");
>> +		phy_attached_print(phydev, "PHY ID %08x IRQ %s %s\n",
>> +				   phydev->phy_id, irq_str,
>> +				   act ? " active" : "");
> I don't want to go round and round with this patch, with feature creep. 
>
> But there are only two drivers which use phy_attached_print() to print
> more than the standard printed by phy_attached_info().
> phy_attached_info() will give you the driver name, so do you need the
> ID? phy_attached_info() prints the irq as a number, rather than a nice
> string.
>
> act is just odd. The loop is effectively phy_find_first(). The act
> means it has found a phy, but not the phy indicated in the platform
> data, but it is going to use it anyway!
>
> So i will give:
>
> Reviewed-by: Andrew Lunn <andrew@...n.ch>
>
> but if you think phy_attached_info() is acceptable, that would be
> great.
>
>     Andrew

Good point, initially I just wanted to propose a fix about logging and
not change the message, in order to avoid to lose informations (but
that's very arguable).
phy_attached_print or phy_attached_info already display the model of the
PHY, so I think that removing PHY ID is okay, because in this case it is
completely useless.

I will post a v3 with your Reviewed-by:

Romain