RE: [PATCH] net: phy: aquantia: Add 10mbps support

[Vyas, Devang nayanbhai]

[AMD Official Use Only - General]

Hi Andrew,

We are using AQR113C Marvell PHY which is CL45 based and based on below check in phy_probe() function:
        if (phydrv->features)
                linkmode_copy(phydev->supported, phydrv->features);
        else if (phydrv->get_features)
                err = phydrv->get_features(phydev);
        else if (phydev->is_c45)
                err = genphy_c45_pma_read_abilities(phydev);    -> it reads capability from PMA register where 10M bit is read-only static and value is 0
        else
                err = genphy_read_abilities(phydev);

Based on PHY datasheet, it supports 10M and we have made the change for the same and verified successfully.

Below code should set the supported field under genphy_c45_pma_read_abilities(), but as the value is 0, we have to set the 10M mode explicitly.

                linkmode_mod_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT,
                                 phydev->supported,
                                 val & MDIO_PMA_EXTABLE_10BT);

Please share your inputs further.

Thanks & Regards,
Devang Vyas

-----Original Message-----
From: Jakub Kicinski <kuba@xxxxxxxxxx> 
Sent: Wednesday, May 3, 2023 8:17 AM
To: Vyas, Devang nayanbhai <Devangnayanbhai.Vyas@xxxxxxx>
Cc: Andrew Lunn <andrew@xxxxxxx>; hkallweit1@xxxxxxxxx; linux@xxxxxxxxxxxxxxx; davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx; pabeni@xxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: Re: [PATCH] net: phy: aquantia: Add 10mbps support

On Wed, 26 Apr 2023 14:54:01 +0200 Andrew Lunn wrote:
> On Wed, Apr 26, 2023 at 01:46:12PM +0530, Devang Vyas wrote:
> > This adds support for 10mbps speed in PHY device's "supported" field 
> > which helps in autonegotiating 10mbps link from PHY side where PHY 
> > supports the speed but not updated in PHY kernel framework.
> 
> Are you saying it is not listed in BMSR that the PHY supports 10 Mbps?
> Bits BMSR_10HALF and BMSR_10FULL are not set?

I didn't see any reply to Andrew's question so dropping this from patchwork for now. It feels like -next material too, so please hold off any reposting until Monday.
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pw-bot: defer