Messages in this thread | | | Date | Thu, 24 Jun 2021 03:17:50 +0200 | From | Andrew Lunn <> | Subject | Re: [net-next: PATCH v3 5/6] net: mvpp2: enable using phylink with ACPI |
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On Wed, Jun 23, 2021 at 11:45:04PM +0200, Marcin Wojtas wrote: > Hi, > > śr., 23 cze 2021 o 22:37 Andrew Lunn <andrew@lunn.ch> napisał(a): > > > > > +static bool mvpp2_use_acpi_compat_mode(struct fwnode_handle *port_fwnode) > > > +{ > > > + if (!is_acpi_node(port_fwnode)) > > > + return false; > > > + > > > + return (!fwnode_property_present(port_fwnode, "phy-handle") && > > > + !fwnode_property_present(port_fwnode, "managed") && > > > + !fwnode_get_named_child_node(port_fwnode, "fixed-link")); > > > > I'm not too sure about this last one. You only use fixed-link when > > connecting to an Ethernet switch. I doubt anybody will try ACPI and a > > switch. It has been agreed, ACPI is for simple hardware, and you need > > to use DT for advanced hardware configurations. > > > > What is your use case for fixed-link? > > > > Regardless of the "simple hardware" definition or whether DSA + ACPI > feasibility, you can still have e.g. the switch left in "unmanaged" > mode (or whatever the firmware configures), connected via fixed-link > to the MAC. The same effect as booting with DT, but not loading the > DSA/switch driver - the "CPU port" can be used as a normal netdev > interface.
You can do this, but i would not recommend it. Without having STP, your network is going to be vulnerable to broadcast storms killing your network.
> I'd also prefer to have all 3 major interface types supported in > phylink, explicitly checked in the driver - it has not been supported > yet, but can be in the future, so let's have them covered in the > backward compatibility check.
Maybe i'm not understanding this correctly, but isn't this condition enforcing there must be a fixed link in order to use the new ACPI binding? But i expect most boards never need a fixed-link, it is optional after all.
Andrew
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