Re: [RFC PATCH net v1] net: phy: aquantia: Set phy speed to 2.5gbps for AQR115c

["Abhishek Chauhan (ABC)" <quic_abchauha@quicinc.com>]

On 9/13/2024 1:01 AM, Maxime Chevallier wrote:
> Hi,
> 
> On Thu, 12 Sep 2024 18:16:35 -0700
> Abhishek Chauhan <quic_abchauha@quicinc.com> wrote:
> 
>> Recently we observed that aquantia AQR115c always comes up in
>> 100Mbps mode. AQR115c aquantia chip supports max speed up to
>> 2.5Gbps. Today the AQR115c configuration is done through
>> aqr113c_config_init which internally calls aqr107_config_init.
>> aqr113c and aqr107 are both capable of 10Gbps. Whereas AQR115c
>> supprts max speed of 2.5Gbps only.
>>
>> Fixes: 0ebc581f8a4b ("net: phy: aquantia: add support for aqr115c")
>> Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com>
>> ---
>>  drivers/net/phy/aquantia/aquantia_main.c | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/net/phy/aquantia/aquantia_main.c b/drivers/net/phy/aquantia/aquantia_main.c
>> index e982e9ce44a5..9afc041dbb64 100644
>> --- a/drivers/net/phy/aquantia/aquantia_main.c
>> +++ b/drivers/net/phy/aquantia/aquantia_main.c
>> @@ -499,6 +499,12 @@ static int aqr107_config_init(struct phy_device *phydev)
>>  	if (!ret)
>>  		aqr107_chip_info(phydev);
>>  
>> +	/* AQR115c supports speed up to 2.5Gbps */
>> +	if (phydev->interface == PHY_INTERFACE_MODE_2500BASEX) {
>> +		phy_set_max_speed(phydev, SPEED_2500);
>> +		phydev->autoneg = AUTONEG_ENABLE;
>> +	}
>> +
> 
> If I get your commit log right, the code above will also apply for
> ASQR107, AQR113 and so on, don't you risk breaking these PHYs if they
> are in 2500BASEX mode at boot?
> 

I was thinking of the same. That this might break something here for other Phy chip. 
As every phy shares the same config init. Hence the reason for RFC. 

> Besides that, if the PHY switches between SGMII and 2500BASEX
> dynamically depending on the link speed, it could be that it's
> configured by default in SGMII, hence this check will be missed.
> 
> Is the AQR115c in the same situation as AQR111 for example, where the
> PMA capabilities reported are incorrect ? If so, you can take the same
> approach as aqr111, which is to create a dedicated .config_init()
> callback for the AQR115c, which sets the max speed, then call
> aqr113c_config_init() from there ?
> 
I think the better way is to have AQR115c its own config_init which sets 
the max speed to 2.5Gbps and then call aqr113c_config_init . 
I will clean up the config_init and 

Thanks for the review comments.

> Maxime