network: optionally bring up interface before joining bridge

Closes #34247.

rules.d/81-net-bridge.rules

@@ -0,0 +1,16 @@
+# do not edit this file, it will be overwritten on update
+
+ACTION=="remove", GOTO="net_bridge_end"
+SUBSYSTEM!="net", GOTO="net_bridge_end"
+
+# Some devices require the port to be up before joining the bridge.
+# In such cases, set ID_NET_BRING_UP_BEFORE_JOINING_BRIDGE to "1".
+
+# Texas Instruments Ethernet device with switchdev mode:
+# https://docs.kernel.org/networking/device_drivers/ethernet/ti/am65_nuss_cpsw_switchdev.html#enabling-switch
+ENV{ID_NET_DRIVER}=="am65-cpsw-nuss", SUBSYSTEMS=="platform", DRIVERS=="am65-cpsw-nuss", \
+  PROGRAM="/usr/sbin/devlink dev param show platform/%b name switch_mode", \
+  RESULT=="*cmode runtime value true*", \
+  ENV{ID_NET_BRING_UP_BEFORE_JOINING_BRIDGE}="1"
+
+LABEL="net_bridge_end"

rules.d/meson.build

@@ -29,6 +29,7 @@ rules = [
                '75-probe_mtd.rules',
                '78-sound-card.rules',
                '80-net-setup-link.rules',
+               '81-net-bridge.rules',
                '81-net-dhcp.rules',
                '90-iocost.rules',
               )],