On Tue, Jan 10, 2017 at 01:08:46PM +0100, Jiri Pirko wrote: > Mon, Jan 09, 2017 at 10:14:36PM CET, ido...@idosch.org wrote: > >On Mon, Jan 09, 2017 at 12:56:48PM -0800, Florian Fainelli wrote: > >> On 01/09/2017 12:48 PM, Ido Schimmel wrote: > >> > Hi Florian, > >> > > >> > On Mon, Jan 09, 2017 at 11:44:59AM -0800, Florian Fainelli wrote: > >> >> Hi all, > >> >> > >> >> This patch series is to resolve a sleeping function called in atomic > >> >> context > >> >> debug splat that we observe with DSA. > >> >> > >> >> Let me know what you think, I was also wondering if we should just > >> >> always > >> >> make switchdev_port_vlan_fill() set SWITCHDEV_F_DEFER, but was afraid > >> >> this > >> >> could cause invalid contexts to be used for rocker, mlxsw, i40e etc. > >> > > >> > Isn't this a bit of overkill? All the drivers you mention fill the VLAN > >> > dump from their cache and don't require sleeping. Even b53 that you > >> > mention in the last patch does that, but reads the PVID from the device, > >> > which entails taking a mutex. > >> > >> Correct. > >> > >> > > >> > Can't you just cache the PVID as well? I think this will solve your > >> > problem. Didn't look too much into the b53 code, so maybe I'm missing > >> > something. Seems that mv88e6xxx has a similar problem. > >> > >> I suppose we could indeed cache the PVID for b53, but for mv88e6xxx it > >> seems like we need to perform a bunch of VTU operations, and those > >> access HW registers, Andrew, Vivien, how do you want to solve that, do > >> we want to introduce a general VLAN cache somewhere in > >> switchdev/DSA/driver? > > > >Truth be told, I don't quite understand why switchdev infra even tries > >to dump the VLANs from the device. Like, in which situations is this > >going to be different from what the software bridge reports? Sure, you > >can set the VLAN filters with SELF and skip the software bridge, but how > >does that make sense in a model where you want to reflect the software > >datapath? > > But the vlans added by rtnl_bridge_setlink & SELF are not tracked by the > bridge and therefore driver needs to dump them. You would have to pass > some flag down to driver when adding SWITCHDEV_OBJ_ID_PORT_VLAN > indicating the need to track the vlan and dump it. Right?
Right, but back to my question - what's the use case for the SELF flag in the switchdev model? Why would I configure a VLAN filter in the hardware but not in the software bridge? The whole point is reflecting the software bridge to the hardware.
