Re: [PATCH v3 1/3] ethdev: add description for KEEP CRC offload

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 19 Jul 2024 17:04:13 +0800
Jie Hai <haijie1@huawei.com> wrote:

> From: Dengdui Huang <huangdengdui@huawei.com>
> 
> The data exceeds the pkt_len in mbuf is inavailable for user.
                                          unavailable

> When KEEP CRC offload is enabled, CRC field length should be
> included in the pkt_len in mbuf. However, almost of drivers
> supported KEEP CRC feature didn't add the CRC data length to
> pkt_len. So it is very necessary to add comments for this.

All drivers must do the same thing, or this is a serious bug
in the drivers. Just changing a comment is not going to be helpful.

To fix this right:
 1. Do a test with one of the original drivers in DPDK that has this
    feature. I would suggest ixgbe, mlx5 or bnxt.

 2. Add a test to the PMD tests that validates this (if there is not
    one already).

 3. Put the documentation in a place where it shows up in user documentation.
    Either in doxygen comment or in doc/guides/nics

 4. Verify that all devices conform to the desired behavior

I can help, but only have some old mlx5 cards to test here.
Just putting comment in ethdev.h is not enough.