Subject: Re: [PATCH net-next 2/3] lan78xx: setting phy features in phy driver

From: Florian Fainelli <[email-masked]>
Date: Wed, 10 Feb 2016 20:05:47 -0800

On 10/02/2016 15:18, [email-masked] wrote:
>>> +static int lan88xx_config_init(struct phy_device *phydev)
>>> +{
>>> +	phydev->supported &= phydev->drv->features;
>>> +	phydev->advertising &= phydev->drv->features;
>>
>> This looks suspicious, phy_probe() takes the driver supported features
>> and assigns it to phydev->supported, and phydev->advertising, is not
>> that working somehow?
>>
>> genphy_config_init() does look at the current MII_BMRS value to
>> determine what is supported by the PHY, and masks it in
>> phydev->supported, so that could indeed be an issue if we had not had a
>> change to mask with the supported modes before.
>>
>> I think we need more explanation here as to what kind of bug you may
>> have been observing, there could be one.
> 
> SUPPORTED_Pause & SUPPORTED_Asym_Pause set at phydev->features  are removed by genphy_config_init().
> As you pointed, it may be better to modify genphy_config_init() than each driver's config_init routine.

I see, that is definitively a bug, we should not clear these bits if the
Ethernet MAC driver asked for them.