On Thu, Mar 18, 2021 at 09:02:22AM -0700, Florian Fainelli wrote: > On 3/18/2021 6:25 AM, Heiner Kallweit wrote: > > On 18.03.2021 10:09, Wong Vee Khee wrote: > >> When using Clause-22 to probe for PHY devices such as the Marvell > >> 88E2110, PHY ID with value 0 is read from the MII PHYID registers > >> which caused the PHY framework failed to attach the Marvell PHY > >> driver. > >> > >> Fixed this by adding a check of PHY ID equals to all zeroes. > >> > > > > I was wondering whether we have, and may break, use cases where a PHY, > > for whatever reason, reports PHY ID 0, but works with the genphy > > driver. And indeed in swphy_read_reg() we return PHY ID 0, therefore > > the patch may break the fixed phy. > > Having said that I think your patch is ok, but we need a change of > > the PHY ID reported by swphy_read_reg() first. > > At a first glance changing the PHY ID to 0x00000001 in swphy_read_reg() > > should be sufficient. This value shouldn't collide with any real world > > PHY ID. > > It most likely would not, but it could be considered an ABI breakage, > unless we filter out what we report to user-space via SIOGCMIIREG and > /sys/class/mdio_bus/*/*/phy_id > > Ideally we would have assigned an unique PHY OUI to the fixed PHY but > that would have required registering Linux as a vendor, and the process > is not entirely clear to me about how to go about doing that. Doesn't that also involve yearly fees? -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
