On Tue, Jul 28, 2020 at 06:06:26PM +1000, Dan Callaghan wrote: > Excerpts from Andrew Lunn's message of 2020-07-24 21:14:36 +02:00: > > Now i could be wrong, but are Ethernet switches something you expect > > to see on ACPI/SBSA platforms? Or is this a legitimate use of the > > escape hatch? > > As an extra data point: right now I am working on an x86 embedded > appliance (ACPI not Device Tree) with 3x integrated Marvell switches. > I have been watching this patch series with great interest, because > right now there is no way for me to configure a complex switch topology > in DSA without Device Tree. > > For the device I am working on, we will have units shipping before these > questions about how to represent Ethernet switches in ACPI can be > resolved. So realistically, we will have to actually configure the > switches using software_node structures supplied by an out-of-tree > platform driver, or some hackery like that, rather than configuring them > through ACPI. Hi Dan I also have an x86 platform, but with a single switch. For that, i have a platform driver, which instantiates a bit banging MDIO bus, and sets up the switch using platform data. This works, but it is limited to internal Copper only PHYs. > An approach I have been toying with is to port all of DSA to use the > fwnode_handle abstraction instead of Device Tree nodes, but that is > obviously a large task, and frankly I was not sure whether such a patch > series would be welcomed. I would actually suggest you look at using DT. We are struggling to get ACPI maintainers involved with really simple things, like the ACPI equivalent of a phandle from the MAC to the PHY. A full DSA binding for Marvell switches is pretty complex, especially if you need SFP support. I expect the ACPI maintainers will actively run away screaming when you make your proposal. DT can be used on x86, and i suspect it is a much easier path of least resistance. Andrew
