[U-Boot] [PATCH V1 1/3] phy: add phy_connect_by_mask

Andy Fleming afleming at gmail.com
Tue Aug 21 02:35:22 CEST 2012


On Monday, August 20, 2012, Troy Kisky wrote:

> It is useful to be able to try a range of
> possible phy addresses to connect.



This seems like it just encourages a bad habit. How do you envision this
working on a system with multiple Ethernet controllers? Or with more PHYs
than Ethernet controllers? While it is often the case that the PHY is the
only one on a bus, I think it's a bad idea to codify that notion in the
driver (I know, it was already like that).

It's best if the driver make the reasonable assumption that its PHY address
is known when it comes up, and let the board code, which can be aware that
the PHY may exist in varying locations, search for the PHY. With that
approach, the driver won't have to change when some board designer makes
the PHY topology even stranger, and I would support a PHYLIB function to do
searching much as you've specified. But the board-specific code needs to be
able to tell the driver definitively which PHY belongs to it.


Andy


More information about the U-Boot mailing list