Le Thu, 9 Feb 2023 00:02:19 +0200, Vladimir Oltean <olteanv@xxxxxxxxx> a écrit : > On Wed, Feb 08, 2023 at 09:38:04AM -0800, Florian Fainelli wrote: > > > + /* Enable TAG always mode for the port, this is actually controlled > > > + * by VLAN_IN_MODE_ENA field which will be used for PVID insertion > > > + */ > > > + reg = A5PSW_VLAN_IN_MODE_TAG_ALWAYS; > > > + reg <<= A5PSW_VLAN_IN_MODE_PORT_SHIFT(port); > > > + a5psw_reg_rmw(a5psw, A5PSW_VLAN_IN_MODE, A5PSW_VLAN_IN_MODE_PORT(port), > > > + reg); > > > > If we always enable VLAN mode, which VLAN ID do switch ports not part of a > > VLAN aware bridge get classified into? > > Good question. I'd guess 0, since otherwise, the VLAN-unaware FDB > entries added with a5psw_port_fdb_add() wouldn't work. The name of the mode is probably missleading. When setting VLAN_IN_MODE with A5PSW_VLAN_IN_MODE_TAG_ALWAYS, the input packet will be tagged _only_ if VLAN_IN_MODE_ENA port bit is set. If this bit is not set, packet will passthrough transparently. This bit is actually enabled in a5psw_port_vlan_add() when a PVID is set and unset when the PVID is removed. Maybe the comment above these lines was not clear enough. > > But the driver has to survive the following chain of commands, which, by > looking at the current code structure, it doesn't: > > ip link add br0 type bridge vlan_filtering 0 > ip link set swp0 master br0 # PVID should remain at a value chosen privately by the driver > bridge vlan add dev swp0 vid 100 pvid untagged # PVID should not change in hardware yet > ip link set br0 type bridge vlan_filtering 1 # PVID should change to 100 now > ip link set br0 type bridge vlan_filtering 0 # PVID should change to the value chosen by the driver > > Essentially, what I'm saying is that VLANs added with "bridge vlan add" > should only be active while vlan_filtering=1. > > If you search for "commit_pvid" in drivers/net/dsa, you'll find a number > of drivers which have a more elaborate code structure which allows the > commands above to work properly. -- Clément Léger, Embedded Linux and Kernel engineer at Bootlin https://bootlin.com
