Messages in this thread | | | Date | Fri, 25 Feb 2022 12:47:40 +0100 | From | Oleksij Rempel <> | Subject | Re: [PATCH net-next v2 1/1] net: dsa: microchip: ksz9477: implement MTU configuration |
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On Thu, Feb 24, 2022 at 11:46:57AM +0200, Vladimir Oltean wrote:
> So where is it failing exactly? Here I guess, because mtu_limit will be > negative? > > mtu_limit = min_t(int, master->max_mtu, dev->max_mtu); > old_master_mtu = master->mtu; > new_master_mtu = largest_mtu + dsa_tag_protocol_overhead(cpu_dp->tag_ops); > if (new_master_mtu > mtu_limit) > return -ERANGE; > > I don't think we can work around it in DSA, it's garbage in, garbage out. > > In principle, I don't have such a big issue with writing the MTU > register as part of the switch initialization, especially if it's global > and not per port. But tell me something else. You pre-program the MTU > with VLAN_ETH_FRAME_LEN + ETH_FCS_LEN, but in the MTU change procedure, > you also add KSZ9477_INGRESS_TAG_LEN (2) to that. Is that needed at all? > I expect that if it's needed, it's needed in both places. Can you > sustain an iperf3 tcp session over a VLAN upper of a ksz9477 port? > I suspect that the missing VLAN_HLEN is masking a lack of KSZ9477_INGRESS_TAG_LEN.
Hm... I assume I need to do something like this: - build kernel with BRIDGE_VLAN_FILTERING - | ip l a name br0 type bridge vlan_filtering 1 ip l s dev br0 up ip l s lan1 master br0 ip l s dev lan1 up bridge vlan add dev lan1 vid 5 pvid untagged ip link add link br0 name vlan5 type vlan id 5
I use lan5@ksz for net boot. As soon as i link lan1@ksz to the br0 with vlan_filtering enabled, the nfs on lan5 will be broken. Currently I have no time to investigate it. I'll try to fix VLAN support in a separate task. What will is acceptable way to proceed with MTU patch?
Regards, Oleksij -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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