On Thu, Dec 17, 2020 at 12:59 AM Ben Greear [off-list ref] wrote:

On 12/16/20 3:09 PM, Ben Greear wrote:

quoted

Hello Eric,

The patch below evidently causes TCP throughput to be about 50Mbps instead of 700Mbps
when using ax200 to upload tcp traffic.

When I disable TSO, performance goes back up to around 700Mbps.

As a followup, when I revert the patch, upload speed goes to ~900Mbps,
so even better than just disabling TSO (I left TSO enabled after reverting the patch).

Thanks,
Ben

Thanks for the report !

It seems drivers/net/wireless/intel/iwlwifi/pcie/tx.c:iwl_fill_data_tbs_amsdu()
calls tso_build_hdr() with extra bytes (SNAP header),
it is not yet clear to me what is broken :/

Can you confirm which driver is used for ax200 ?

I see tso_build_hdr() also being used from
drivers/net/wireless/intel/iwlwifi/queue/tx.c