Re: [PATCH bpf-next v2 2/3] net: stmmac: Add txtime support to XDP ZC

[Jesper Dangaard Brouer]

On 12/1/23 07:24, Song Yoong Siang wrote:
> This patch enables txtime support to XDP zero copy via XDP Tx
> metadata framework.
>
> Signed-off-by: Song Yoong Siang<yoong.siang.song@xxxxxxxxx>
> ---
>   drivers/net/ethernet/stmicro/stmmac/stmmac.h      |  2 ++
>   drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 13 +++++++++++++
>   2 files changed, 15 insertions(+)

I think we need to see other drivers using this new feature to evaluate
if API is sane.

I suggest implementing this for igc driver (chip i225) and also for igb
(i210 chip) that both support this kind of LaunchTime feature in HW.

The API and stmmac driver takes a u64 as time.
I'm wondering how this applies to i210 that[1] have 25-bit for
LaunchTime (with 32 nanosec granularity) limiting LaunchTime max 0.5
second into the future.
And i225 that [1] have 30-bit max 1 second into the future.


[1] 
https://github.com/xdp-project/xdp-project/blob/master/areas/tsn/code01_follow_qdisc_TSN_offload.org