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

[Jie Hai]

Hi, Stephen Hemminger

Thanks for your review.
I will add doc and fix on drivers in the next version.
The test will be done later.

On 2024/11/23 1:10, Stephen Hemminger wrote:
> On Fri, 19 Jul 2024 17:04:13 +0800
> Jie Hai <haijie1 at huawei.com> wrote:
> 
>> From: Dengdui Huang <huangdengdui at 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.
> I can test it on ixgbe and mlx5.
>   2. Add a test to the PMD tests that validates this (if there is not
>      one already).
> 
Maybe later and not come with this patchset.
>   3. Put the documentation in a place where it shows up in user documentation.
>      Either in doxygen comment or in doc/guides/nics
> 
Will add in the next version.
>   4. Verify that all devices conform to the desired behavior
> 
> I can help, but only have some old mlx5 cards to test here.
Thanks.
> Just putting comment in ethdev.h is not enough.
> 

Thanks,
Jie Hai

>