Re: stmmac: zero udp checksum
From: Julian Labus <hidden>
Date: 2021-04-05 19:31:00
On 05.04.21 18:42, Andrew Lunn wrote:
Have you looked at where it actually drops the packet? Is it one of https://elixir.bootlin.com/linux/latest/source/drivers/net/ethernet/stmicro/stmmac/norm_desc.c#L95 or https://elixir.bootlin.com/linux/latest/source/drivers/net/ethernet/stmicro/stmmac/enh_desc.c#L87 It could be, you need to see if the checksum has fail, then check if the checksum is actually zero, and then go deeper into the frame and check if it is a vxlan frame. It could be the linux software checksum code knows about this vxlan exception, so you can just run that before deciding to drop the frame. Andrew
No, I've not yet checked where the packet is actually dropped. This is my first time debugging a network problem in the kernel and I have little to no knowledge how this rx offloading works. But I don't think it happens in norm_desc.c#L95 as I would expect the ipc_csum_error counter to increase. But the only counters in "ethtool -S" which are increasing are mmc_rx_udp_err and mmc_rx_udp_err_octets. I'll try to get more information. Julian