On Sat, May 04, 2019 at 11:40:53PM +0800, Chuanhong Guo wrote: > Hi! > > On Mon, Apr 22, 2019 at 9:28 PM Andrew Lunn <andrew@xxxxxxx> wrote: > > [...] > > > + /* > > > + * On most (all?) Atheros/QCA SoCs dual eth interfaces are not equal. > > > + * > > > + * That is to say eth0 can not work independently. It only works > > > + * when eth1 is working. > > > + */ > > > > Please could you explain that some more? Is there just one MDIO bus > > shared by two ethernet controllers? If so, it would be better to have > > the MDIO bus controller as a separate driver. > > mdio registers exists on both ethernet blocks. And due to how reset > works on this ethernet IP, it's hard to split it into a separated > driver. (Only asserting both eth and mdio resets together will reset > everything including register values.) > The reason why gmac1 should be brought up first is that on some chips, > mdio on gmac0 connects to nothing and phy used by gmac0 is on mdio bus > of gmac1. It could be implemented as mfd device. Not sure if it is worth it. Pro/contra argumentation is welcome. -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
