On Thu, Apr 28, 2016 at 05:44:14PM +0200, Nicolas Ferre wrote: > Le 28/04/2016 16:46, Nathan Sullivan a écrit : > > Since of_mdiobus_register and mdiobus_register will scan automatically, > > do not manually scan for PHY devices in the macb ethernet driver. Doing > > so will result in many nonexistent PHYs on the MDIO bus if the MDIO > > lines are floating or grounded, such as when they are not used. > > > > Signed-off-by: Nathan Sullivan <nathan.sulli...@ni.com> > > Well, as explained in the commit message that added this feature and in > the comment, if no phy is specified in the DT we end up without phy... > > There are AT91 platforms which lack specification for the phy node in > the DT. So, I don't know if there is a better way to deal with this case > but I see this removal as risky. > > Bye, > > Nicolas Ferre
Hmm, are AT91 platforms special in this regard? As far as I can tell, this driver (macb) and Marvell PXA are the only ethernet drivers that call mdiobus_scan directly, and PXA does it on a known address. I do see that there are trees that use macb and don't have a phy listed, which is unfortunate. Another way to fix our issue would be to consider all 0x0s a bad ID in mdiobus_scan, so grounded MDIO lines do not get PHYs scanned. Or we could add a DT property to disable the manual scan. I'm not sure what the correct solution is, do you have a preference?
